View source for United States dollar

{{redirect|USD}}
{{Use mdy dates|date=March 2013}}
{{Primary sources|date=April 2010}}
{{pp-move-indef}}
{{Infobox Currency
|currency_name_in_local = 
| image_1 = USDnotes.png
| image_title_1 = [[Federal Reserve Note]]s
|iso_code = USD (num. 840)
|using_countries = {{flag|United States}}<br/>{{flag|El Salvador}}<ref>{{cite web|url=https://www.cia.gov/library/publications/the-world-factbook/geos/es.html|title=El Salvador|publisher=[[CIA World Factbook]]|accessdate=October 27, 2010|date=October 21, 2010|quote=The US dollar became El Salvador's currency in 2001}}</ref><br/>{{flag|Panama}}<ref>Alongside [[Panamanian balboa]] coins</ref><br />{{flag|Ecuador}}<ref>{{cite web|url=https://www.cia.gov/library/publications/the-world-factbook/geos/ec.html|title=Ecuador|publisher=[[CIA World Factbook]]|accessdate=October 27, 2010|date=October 18, 2010|quote=The dollar is legal tender}}</ref><br />{{flag|East Timor}}<ref>{{cite web|url=http://www.bancocentral.tl/en/currency.asp|title=Central Bank of Timor-Leste|accessdate=May 22, 2013|quote=The official currency of Timor-Leste is the United States dollar, which is legal tender for all payments made in cash.}}</ref>

{{Collapsible list|title = U.S. territories
|<br>''{{flag|Panama Canal Zone}} (1903–1979)<br/>{{flag|Puerto Rico}}<br />{{flag|Northern Mariana Islands}}<br />{{flag|U.S. Virgin Islands}}<br />{{flag|American Samoa}}<br />{{flag|Guam}}<br />{{flag|Trust Territory of the Pacific Islands}} (1947–1994)<br/>{{flag|United States Minor Outlying Islands}}<ref>{{cite web|url=http://www.bes.dnb.nl/en/frequently_asked_questions?faq_id=6#faq-6|accessdate=January 1, 2011|title=Frequently asked questions}}</ref>''
}}
|unofficial_users =
{{Collapsible list|titlestyle = font-weight:normal; background:transparent; text-align:left;
|title = 17 other countries
|{{flag|Afghanistan}}<ref>U.S. Dollar and [[Pakistani rupee]] are widely accepted.</ref><br />{{flag|The Bahamas}}<ref>Bahamian dollar tied 1:1 to USD, both accepted interchangeably.</ref><br />{{Flag|Barbados}}<ref>Barbados dollar tied at about 2:1, both accepted. Visiting Barbados FAQ: [http://www.investbarbados.org/faq_visiting.php#currency What is the local currency?], Invest Barbados</ref><br />{{flag|Cambodia}}<ref>Alongside [[Cambodian riel]]</ref><br />{{flag|Haiti}}<br />{{flag|Lebanon}}<ref>U.S. dollar is widely used alongside the [[Lebanese Pound]] at a fixed exchange rate of 1:1,500</ref> <br />{{flag|Liberia}}<br />{{flag|Maldives}}<br />{{flag|Marshall Islands}}<br />{{flag|Federated States of Micronesia}}<br />{{flag|Palau}}<br />{{flag|Zimbabwe}}<ref>Alongside [[Zimbabwean dollar]] (suspended indefinitely from April 12, 2009), Euro, [[Pound Sterling]], [[South African rand]] and [[Botswana pula]]. The U.S. Dollar has been adopted as the official currency for all government transactions.</ref><br />{{flag|Guatemala}}
}}
{{Collapsible list|titlestyle = font-weight:normal; background:transparent; text-align:left;
|title = 6 non-U.S. territories
|<br />{{flag|Caribbean Netherlands}} ([[Netherlands]])<small><br />{{flag|British Virgin Islands}} <small>(UK)</small><br />{{flag|Turks and Caicos Islands}} <small>(UK; alongside [[Bahamian dollar]] from 25 May 2013)</small><br />{{flag|Cayman Islands}} <small>(UK; de facto)</small><br />{{flag|Bermuda}} <small>(UK)''</small><ref>Alongside [[Bermudian dollar]]</ref><br> {{flag|British Indian Ocean Territory}} (''de facto''<ref>[http://www.fco.gov.uk/en/travel-and-living-abroad/travel-advice-by-country/country-profile/asia-oceania/british-indian-ocean-territory?profile=all FCO country profile]</ref><ref>{{cite web|url=http://wwp.greenwichmeantime.com/time-zone/asia/british-indian-ocean-territory/currency-british-indian-ocean-territory/index.htm |title=British Indian Ocean Territory Currency |publisher=Wwp.greenwichmeantime.com |date=2013-03-06 |accessdate=2013-05-05}}</ref>)
}}
|pegged_by =
{{Collapsible list
 |title = 23 currencies
 |''[[Aruban florin]]''<br />[[Bahamian dollar]] (at par)<br />[[Bahraini dinar]]<br />[[Barbadian dollar]]<br />[[Belize dollar]]<br />''[[Bermudian dollar]]'' (at par)<br />''[[Cayman Islands dollar]]''<br />[[Cuban convertible peso]]<br />[[Djiboutian franc]]<br />[[East Caribbean dollar]]<br />[[Eritrean nakfa]]<br />''[[Hong Kong dollar]]'' (narrow band)<br />[[Jordanian dinar]]<br />[[Lebanese pound]]<br />''[[Netherlands Antillean gulden]]''<br />[[Omani rial]]<br />[[Panamanian balboa]] (at par)<br />[[Sealand dollar]]{{Citation needed|date=January 2012}}<br />[[Qatari riyal]]<br />[[Saudi riyal]]<br />[[Trinidad and Tobago dollar]]<br />[[United Arab Emirates dirham]]<br />[[Venezuelan bolívar]]
}}
|inflation_rate = 1.75&nbsp;% June 2013
|inflation_source_date = [http://inflationdata.com/inflation/Inflation_Rate/HistoricalInflation.aspx?dsInflation_currentPage=0 inflationdata.com]''
| inflation_method = [[consumer price index|CPI]]
|subunit_ratio_1 = 1/10
|subunit_name_1 = [[Dime (United States coin)|Dime]]
|subunit_ratio_2 = 1/100
|subunit_name_2 = [[Cent (currency)|Cent]]
|subunit_ratio_3 = 1/1000
|subunit_name_3 = [[Mill (currency)|Mill]] (''used in accounting and by almost all fuel stations'')
|symbol =[[Dollar sign|$]]
|symbol_subunit_4 =[[cent sign#Symbol|¢]]
|nickname = Buck, bill, bean, paper, smackeroo, dead president, smacker, and [[United States Note|greenback]]. Plural: dough, green, bread, bones, simoleons, skrilla, (bank) clams, mint sauce {{Citation needed|reason=I've never heard mint sauce used to refer to money? Didn't find much on google either?|date=August 2013}}. Also, Washingtons, Jeffersons, Lincolns, Jacksons, Benjamins, Grants, and Hamiltons are used based on denomination; also [[peso]] in [[Puerto Rico]], and [[piastre]] in Cajun [[Louisiana]].
|frequently_used_coins = [[cent (United States coin)|1¢]], [[Nickel (United States coin)|5¢]], [[Dime (United States coin)|10¢]], [[Quarter (United States coin)|25¢]]<!-- The denominations are written as they appear on the coins per infobox style at http://en.wikipedia.org/wiki/Template_talk:Infobox Currency -->
|rarely_used_coins = [[Half dollar (United States coin)|50¢]], [[Dollar (United States coin)|$1]]
|coin_article = Coins of the United States dollar
|frequently_used_banknotes = [[United States one-dollar bill|$1]], [[United States five-dollar bill|$5]], [[United States ten-dollar bill|$10]], [[United States twenty-dollar bill|$20]], [[United States fifty-dollar bill|$50]], [[United States one hundred-dollar bill|$100]]
|rarely_used_banknotes = [[United States two-dollar bill|$2]]<br/>Not Circulated: [[United States five hundred dollar bill|$500]], [[Large denominations of United States currency#$1,000 dollar bill|$1,000]], [[United States five thousand dollar bill|$5,000]], [[$10,000 bill|$10,000]], [[United States one hundred thousand-dollar bill|$100,000]]
|banknote_article = Federal Reserve Note
|issuing_authority = [[Federal Reserve System]]
|issuing_authority_website = www.federalreserve.gov
|printer = [[Bureau of Engraving and Printing]]
|printer_website = www.moneyfactory.gov
|mint = [[United States Mint]]
|mint_website = www.usmint.gov
|footnotes =
}}

The '''United States dollar''' ([[currency sign|sign]]: '''[[Dollar sign|$]]'''; [[ISO 4217|code]]: '''USD'''; also abbreviated '''US$'''), is referred to as the '''U.S. dollar''' or '''American dollar. '''It''' '''is the official currency of the [[United States]] and its [[Territories of the United States|overseas territories]]. It is divided into 100 smaller units called [[cent (currency)|cents]].

The U.S. dollar is the currency most used in [[international trade|international transactions]] and is one of the world's most dominant [[reserve currency|reserve currencies]].<ref>{{cite web|url=http://www.federalreserve.gov/pf/pdf/pf_4.pdf |title=The Implementation of Monetary Policy – The Federal Reserve in the International Sphere|format=PDF |accessdate=August 24, 2010}}</ref> Several countries [[dollarization|use it as their official currency]], and in many others it is the [[de facto currency|''de facto'' currency]].<ref>Benjamin J. Cohen, ''The Future of Money'', Princeton University Press, 2006, ISBN 0-691-11666-0; ''cf.'' "the dollar is the de facto currency in Cambodia", Charles Agar, ''[[Frommer's]] Vietnam'', 2006, ISBN 0-471-79816-9, p. 17</ref>  It is also used as the sole currency in two [[British Overseas Territories|British Overseas Territories:]] The [[British Virgin Islands]] and the [[Turks and Caicos]] islands.

==Overview==
The [[United States Constitution|Constitution of the United States of America]] provides that the [[United States Congress]] has the power "To coin money".<ref>{{cite web|url=http://topics.law.cornell.edu/constitution/articlei#section8 |title=Paragraph 5 of Section 8 of Article 1 of the Constitution of the United States of America |publisher=Topics.law.cornell.edu |accessdate=August 24, 2010}}</ref> Laws implementing this power are currently codified in Section 5112 of Title 31 of the United States Code. Section 5112 prescribes the forms, in which the United States dollars should be issued.<ref name="Section5112">{{cite web
|url = http://www.law.cornell.edu/uscode/31/5112.html
|title = Section 5112 of Title 31 of the United States Code
|accessdate =March 16, 2010
}}</ref> These coins are both designated in Section 5112 as "legal tender" in payment of debts.<ref name="Section5112"/> The [[Sacagawea dollar]] is one example of the copper alloy dollar. The pure silver dollar is known as the [[American Silver Eagle]]. Section 5112 also provides for the minting and issuance of other coins, which have values ranging from one cent to fifty dollars.<ref name="Section5112"/> These other coins are more fully described in [[Coins of the United States dollar]].

The Constitution provides that "a regular Statement and Account of the Receipts and Expenditures of all public Money shall be published from time to time".<ref>{{cite web|url=http://topics.law.cornell.edu/constitution/articlei#section9 |title=Paragraph 7 of Section 9 of Article 1 of the Constitution of the United States of America |publisher=Topics.law.cornell.edu |accessdate=August 24, 2010}}</ref> That provision of the Constitution is made specific by Section 331 of Title 31 of the United States Code.<ref>{{cite web|url=http://www.law.cornell.edu/uscode/html/uscode31/usc_sec_31_00000331----000-.html |title=Section 331 of Title 31 of the United States Code |publisher=Law.cornell.edu |date=August 6, 2010 |accessdate=August 24, 2010}}</ref> The sums of money reported in the "Statements" are currently being expressed in U.S. dollars (for example, see the ''2009 Financial Report of the United States Government'').<ref>{{cite web|url=http://www.gao.gov/financial/fy2009/09frusg.pdf |title=2009 Financial Report of the United States Government |format=PDF |accessdate=August 24, 2010}}</ref> The U.S. dollar may therefore be described as the [[unit of account]] of the United States.

The word "dollar" is one of the words in the first paragraph of [[Denied powers|Section 9]] of Article 1 of the U.S. Constitution. In that context, "dollars" is a reference to the [[Spanish milled dollar]], a coin that had a [[monetary]] value of 8 Spanish units of currency, or [[Spanish real|reales]]. In 1792 the U.S. Congress adopted legislation titled ''[[Coinage Act of 1792|An act establishing a mint, and regulating the Coins of the United States]]''. Section 9 of that act authorized the production of various coins, including "DOLLARS OR UNITS—each to be of the value of a Spanish milled dollar as the same is now current, and to contain three hundred and seventy-one grains and four sixteenth parts of a grain of pure, or four hundred and sixteen grains of standard silver". Section 20 of the act provided, "That the money of account of the United States shall be expressed in dollars, or units... and that all accounts in the public offices and all proceedings in the courts of the United States shall be kept and had in conformity to this regulation". In other words, this act designated the United States dollar as the ''[[Currency|unit of currency]]'' of the United States.

Unlike the Spanish milled dollar the U.S. dollar is based upon a decimal system of values. In addition to the dollar the coinage act officially established monetary units of ''[[mill (currency)]]'' or one-thousandth of a dollar (symbol [[Mill (currency)|₥]]), ''[[Cent (United States coin)|cent]]'' or one-hundredth of a dollar (symbol ¢), ''[[Dime (United States coin)|dime]]'' or one-tenth of a dollar, and ''[[eagle (United States coin)|eagle]]'' or ten dollars, with prescribed weights and composition of gold, silver, or copper for each. It was proposed in the mid-1800s that one hundred dollars be known as a ''union'', but no union coins were ever struck and only patterns for the $50 [[half union]] exist. However, only cents are in everyday use as divisions of the dollar; "dime" is used solely as the name of the [[Dime (U.S. coin)|coin]] with the value of 10¢, while "eagle" and "mill" are largely unknown to the general public, though mills are sometimes used in matters of tax levies, and gasoline prices are usually in the form of $X.XX9 per gallon, e.g., $3.599, sometimes written as $3.59{{frac|9|10}}. When currently issued in circulating form, denominations equal to or less than a dollar are emitted as [[Coins of the United States dollar|U.S. coins]] while denominations equal to or greater than a dollar are emitted as [[Federal Reserve Note|Federal Reserve notes]] (with the exception of gold, silver and platinum coins valued up to $100 as legal tender, but worth far more as bullion). Both one-dollar coins and notes are produced today, although the note form is significantly more common. In the past, "paper money" was occasionally issued in denominations less than a dollar ([[fractional currency]]) and gold coins were issued for [[circulation (currency)|circulation]] up to the value of $20 (known as the "[[double eagle]]," discontinued in the 1930s). The term ''[[Eagle (United States coin)|eagle]]'' was used in the [[Coinage Act of 1792]] for the denomination of ten dollars, and subsequently was used in naming gold coins.  Paper currency less than one dollar in denomination, known as "fractional currency," was also sometimes pejoratively referred to as "shinplasters."  In 1854, [[James Guthrie (American politician)|James Guthrie]], then [[Secretary of the Treasury]], proposed creating $100, $50 and $25 gold coins, which were referred to as a "Union," "Half Union," and "Quarter Union,"<ref>Mehl, B. Max. "United States $50.00 Gold Pieces, 1877", in ''Star Rare Coins Encyclopedia and Premium Catalogue'' (20th edition, 1921)</ref> thus implying a denomination of 1 Union = $100.
[[File:One US dollar 1917.jpg|200px|right|thumb|Series of 1917 [[United States one-dollar bill|$1 United States bill]]]]
Today, USD notes are made from cotton fiber paper, unlike most common paper, which is made of wood fiber. U.S. coins are produced by the [[United States Mint]]. U.S. dollar [[banknote]]s are printed by the [[Bureau of Engraving and Printing]] and, since 1914, have been issued by the [[Federal Reserve]]. The "[[large-sized note]]s" issued before 1928 measured {{convert|7.42|in|mm}} by {{convert|3.125|in|mm}}; [[small-sized note]]s, introduced that year, measure {{convert|6.14|in|mm}} by {{convert|2.61|in|mm}} by {{convert|0.0043|in|mm}}.  When the current, smaller sized U.S. currency was introduced it was referred to as Philippine-sized currency because the Philippines had previously adopted the same size for its legal currency.

==Etymology==
{{Further|Dollar}}

In the 16th century, Count [[Hieronymus Schlick]] of [[Bohemia]] began minting coins known as ''Joachimstalers'' (from German ''thal,'' or nowadays usually ''Tal,'' "valley", cognate with "dale" in English), named for [[Jáchymov|Joachimstal]], the valley where the silver was mined ([[St. Joachim]]'s Valley, now Jáchymov; then part of the [[Holy Roman Empire]], now part of the [[Czech Republic]]).<ref name="NatGeo">National Geographic. June 2002. p. 1. ''Ask Us''.</ref> Joachimstaler was later shortened to the German ''[[Taler]]'', a word that eventually found its way into Danish and Swedish as ''daler'', Dutch as ''daler'' or ''daalder'', Ethiopian as ታላሪ (talari), Hungarian as ''tallér'', Italian as ''tallero'', and English as ''dollar''.<ref name="NatGeo"/> Alternatively, ''thaler'' is said to come from the German coin ''[[Guldengroschen]]'' ("great guilder", being of silver but equal in value to a gold guilder), minted from the silver from Joachimsthal.

The coins minted at Joachimsthal soon lent their name to other coins of similar size and weight from other places. One such example, was a Dutch coin depicting a lion, hence its Dutch name [[leeuwendaalder|leeuwendaler]] ([[English language|English]] ''lion'' daler).

The leeuwendaler was authorized to contain 427.16 grains of .750 fine silver and passed locally for between 36 to 42 [[stuiver]]s. It was lighter than the large denomination coins then in circulation, thus it was more advantageous for a Dutch merchant to pay a foreign debt in leeuwendalers and it became the coin of choice for foreign trade.

The leeuwendaler was  popular in the [[Dutch East Indies]] and in the Dutch [[New Netherland|New Netherland Colony]] ([[New York]]), and circulated throughout the [[Thirteen Colonies]] during the 17th and early 18th centuries. It was also popular throughout Eastern Europe where it lead to the current Romanian and Moldovan currency being called [[Romanian leu|leu]](literally "lion").

Among the English-speaking community the coin came popularly to be known as lion dollar – and is in fact the origin of the name Dollar.<ref>{{cite web|url=http://coins.lakdiva.org/netherlands/1644_wes_lion_daalder_ag.html |title=Dutch Colonial - Lion Dollar |publisher=Coins.lakdiva.org |date= |accessdate=2013-05-05}}</ref> The modern American-English pronunciation of ''dollar'' is still remarkably close to the 17th-century Dutch pronunciation of ''daler''.<ref name="etymologiebank.nl">{{cite web|url=http://www.etymologiebank.nl/trefwoord/dollar |title=etymologiebank.nl |publisher=etymologiebank.nl |date= |accessdate=2013-05-05}}</ref>

By analogy with this lion dollar, Spanish pesos – with the same weight and shape as the lion dollar – came to be known as ''Spanish'' dollars.<ref name="etymologiebank.nl"/> By the mid-18th century, the lion dollar had been replaced by [[Spanish dollar]], the famous "piece of eight", which were distributed widely in the [[Spanish colonization of the Americas|Spanish colonies in the New World]] and in the [[Philippines]].<ref name = "nqteor">{{cite journal
  | last =Julian
  | first =R.W.
  | title =All About the Dollar
  | publisher =Numismatist
  | year = 2007
  | page =41 }}</ref>
Eventually dollar became the name of the  first official American currency.

===Nicknames===
{{Refimprove section|date=December 2012}}

The [[colloquialism]] "''buck''" (much like the British word "''[[pound sterling|quid]]''" for the pound sterling) is often used to refer to dollars of various nations, including the U.S. dollar. This term, dating to the 18th century, may have originated with the colonial leather trade. It may also have originated from a [[poker]] term.<ref>{{cite web |title=Buck |publisher=Online Etymology Dictionary |url=http://www.etymonline.com/index.php?search=buck&searchmode=term |accessdate=November 10, 2011 }}</ref> "''[[United States Note|Greenback]]''" is another nickname originally applied specifically to the 19th century [[Demand Note]] dollars created by [[Abraham Lincoln]] to finance the costs of the [[United States Civil War|Civil War]] for the [[Northern United States|North]].<ref>{{cite web |title=Paper Money Glossary |publisher=Littleton Coin Company |url=http://www.littletoncoin.com/webapp/wcs/stores/servlet/Display%7C10001%7C10001%7C-1%7C%7CLearnNav%7CGlossaries-Paper.html |accessdate=November 7, 2011 }}</ref> The original note was printed in black and green on the back side. It is still used to refer to the U.S. dollar (but not to the dollars of other countries). Other well-known names of the dollar as a whole in denominations include "''greenmail''", "''green''" and "''dead presidents''" (the last because deceased presidents are pictured on the bills).

A "''[[1000 (number)#In popular culture|grand]]''", sometimes shortened to simply "''G''", is a common term for the amount of $1,000. The suffix "''K''" or "''k''" (from "[[kilo-]]") is also commonly used to denote this amount (such as "$10k" to mean $10,000). A "''large''" or "''stack''", it is usually a reference to a multiple of $1,000 (such as "''fifty large''" meaning $50,000). The $100 bill is nicknamed "''Benjamin''" or "''Franklin''" (after [[Benjamin Franklin]], "''C-note''" (C being the [[Roman numeral]] for 100), "''Century note''" or "''bill''" (e.g. "''two bills''" being $200). The $20 bill is referred to as "''double sawbuck''", "''Jackson''" (after [[Andrew Jackson]]), or "double eagle". The $10 bill—as "''sawbuck''", "''ten-spot''" or "''Hamilton''" (after [[Alexander Hamilton]]). The $5 bill as "''fin''", "''fiver''" or "''five-spot''". The $2 bill is sometimes called "''deuce''", "''Tom''", or "''Jefferson''" (after [[Thomas Jefferson]]). The $1 bill as a "''single''" or "''buck''". The dollar has also been referred to as a "''bone''" and "''bones''" in plural (e.g. "''twenty bones''" is equal to $20). The newer designs are sometimes referred to as "''Bigface''" bills or "[[Monopoly (game)|Monopoly]] money".

In French-speaking areas of [[Louisiana]], the dollar is referred to as "''piastre''" (pronounced "pee-as") and the French holdover "''sous''" (pronounced "soo") is used to refer to the cent.

In [[El Salvador]], the dollar replaced the [[Salvadoran colón]] under the presidency of [[Francisco Flores Pérez]].

In [[Panama]], the equivalent of buck is "''palo''" (literally "stick"). Also, the [[Panamanian balboa]] is directly tied to the U.S. dollar, and USDs are frequently used in place of the minted Panamanian currency.

In [[Ecuador]], the dollar is referred to as "''plata''" (literally "silver").

In [[Peru]], a nickname for the U.S. dollar is "''coco''", which is a pet name for ''Jorge'' ("''George''" in Spanish), a reference to the portrait of [[George Washington]] on the $1 note.

[[Puerto Rico|Puerto Ricans]], both living in [[Puerto Rico]] and in the United States, may refer to the dollar as "''[[peso]]''".

In some places in [[Mexico]], prices in U.S. dollars are referred to as "''en americano''" ("in American"), or ''en oro'' ("in gold") with the word "peso" used in Mexico primarily to refer to the [[Mexican peso]].

Cubans call the U.S. dollar "fula". Loosely translated from Cuban jargon meaning bad. Possession of American money was penalized before the mid-1990s, hence the nickname.

==Dollar sign==
{{Main|Dollar sign}}
[[File:Potosi Real.jpg|thumb|Silver ''[[Spanish real|real]]'' of 1768]]
The symbol '''$''', usually written before the numerical amount, is used for the U.S. dollar (as well as for many other currencies). The sign  was the result of a late 18th-century evolution of the [[scribal abbreviation]] "p<sup>s</sup>" for the [[peso]]. The ''p'' and the ''s'' eventually came to be written over each other giving rise to ''$''.<ref>[[Florian Cajori|Cajori, Florian]] ([1929]1993). ''[http://books.google.com/books?id=7juWmvQSTvwC&pg=RA1-PA22&dq=isbn:0486677664#PRA1-PA22,M1 A History of Mathematical Notations]'' (Vol. 2). New York: Dover, 15–29. ISBN 0-486-67766-4</ref><ref>Aiton, Arthur S. and Benjamin W. Wheeler (May 1931). [http://links.jstor.org/sici?sici=0018-2168%28193105%2911%3A2%3C198%3ATFAM%3E2.0.CO%3B2-Q "The First American Mint"], ''The Hispanic American Historical Review'' '''11 (2)''', 198 and note 2 on 198.</ref><ref>{{cite book | last = Nussbaum | first = Arthur | authorlink = Arthur Nussbaum | title = A History of the Dollar | publisher = Columbia University Press | year = 1957 | location = New York | page = 56 |quote= The dollar sign, $, is connected with the peso, contrary to popular belief, which considers it to be an abbreviation of 'U.S.' The two parallel lines represented one of the many abbreviations of 'P,' and the 'S' indicated the plural. The abbreviation '$.' was also used for the peso, and is still used in Argentina.}}</ref><ref>[http://www.moneyfactory.gov/faqlibrary.html "What is the origin of the $ Sign?"], US Bureau of Engraving and Printing website</ref>

Another popular explanation is that it comes from the [[Pillars of Hercules]] on the [[Coat of arms of Spain|Spanish Coat of arms]] on the [[Spanish dollars]] that were minted in the [[New World]] mints in [[Mexico City]], [[Potosí]], Bolivia, and in [[Lima]], Peru. These [[Pillars of Hercules]] on the silver [[Spanish dollar]] coins take the form of two vertical bars (||) and a swinging cloth band in the shape of an "S".

Yet another fictional explanation suggests that the dollar sign was formed from the capital letters U and S written or printed one on top of the other. This theory, popularized by novelist [[Ayn Rand]] in ''[[Atlas Shrugged]]'',<ref>Rand, Ayn. ''Atlas Shrugged''. 1957. Signet. 1992. p628</ref> does not consider the fact that the symbol was already in use before the formation of the United States.<ref>{{cite book | last = James | first = James Alton | title = Oliver Pollock: The Life and Times of an Unknown Patriot | publisher = Books for Libraries Press | year = 1970 | origyear = 1937 | location = Freeport | page = 356 | url = http://books.google.com/books?id=kht_DEllNccC | isbn = 978-0-8369-5527-9}}</ref>

==History==
{{See also|History of the United States dollar}}
[[File:500-2f.jpg|200px|right|thumb|Obverse of rare 1934 $500 Federal Reserve Bill, featuring a portrait of President [[William McKinley]].]]
[[File:500-2b.jpg|200px|right|thumb|Reverse of $500 Bill]]
The first dollar coins issued by the [[United States Mint]] (founded 1792) were similar in size and composition to the [[Spanish dollar]]. The Spanish, U.S. silver dollars, and Mexican silver pesos circulated side by side in the United States, and the Spanish dollar and Mexican peso remained legal tender until [[Coinage Act of 1857|1857]]. The coinage of various English colonies also circulated. The [[lion dollar]] was popular in the Dutch New Netherland Colony (New York), but the lion dollar also circulated throughout the English colonies during the 17th century and early 18th century. Examples circulating in the colonies were usually worn so that the design was not fully distinguishable, thus they were sometimes referred to as "dog dollars".<ref>{{cite web|url=http://www.coins.nd.edu/ColCoin/ColCoinIntros/Lion-Dollar.intro.html |title=The Lion Dollar: Introduction |publisher=Coins.nd.edu |accessdate=August 24, 2010}}</ref>

The U.S. dollar was created by the Constitution and defined by the [[Coinage Act of 1792]]. It specified a "dollar" to be based in the Spanish milled dollar and of 371 grains and 4 sixteenths part of a grain of pure or {{convert|416|gr}} of standard silver  and an "eagle" to be 247 and 4 eighths of a grain or {{convert|270|gr}} of gold (again depending on purity).<ref>{{cite web|last=Mint|first=U.S.|title=Coinage Act of 1792|url=http://www.usmint.gov/historianscorner/?action=docDetail&id=326|publisher=U.S. treasury}}</ref> The choice of the value 371 grains arose from [[Alexander Hamilton]]'s decision to base the new American unit on the average weight of a selection of worn Spanish dollars. Hamilton got the treasury to weigh a sample of Spanish dollars and the average weight came out to be 371 grains. A new Spanish dollar was usually about 377 grains in weight, and so the new U.S. dollar was at a slight discount in relation to the Spanish dollar.

The [[Coinage Act of 1792]] set the value of an eagle at 10 dollars, and the dollar at 1/10 eagle. It called for 90% silver alloy coins in denominations of 1, 1/2, 1/4, 1/10, and 1/20 dollars; it called for 90% gold alloy coins in denominations of 1, 1/2, 1/4, and 1/10 eagles.

The value of gold or silver contained in the dollar was then converted into relative value in the economy for the buying and selling of goods. This allowed the value of things to remain fairly constant over time, except for the influx and outflux of gold and silver in the nation's economy.

The early currency of the United States did not exhibit faces of presidents, as is the custom now. In fact, George Washington was against having his face on the currency, a practice he compared to the policies of European monarchs.{{Citation needed|date=September 2011}} The currency as we know it today did not get the faces they currently have until after the early 20th century; before that "heads" side of coinage used profile faces and striding, seated, and standing figures from Greek and Roman mythology and composite native Americans. The last coins to be converted to profiles of historic Americans were the dime (1946) and the Dollar (1971).

For articles on the currencies of the colonies and states, see [[Connecticut pound]], [[Delaware pound]], [[Georgia pound]], [[Maryland pound]], [[Massachusetts pound]], [[New Hampshire pound]], [[New Jersey pound]], [[New York pound]], [[North Carolina pound]], [[Pennsylvania pound]], [[Rhode Island pound]], [[South Carolina pound]] and [[Virginia pound]].

===Continental currency===
{{See also|Continental currency}}
[[File:Continental Currency One-Third-Dollar 17-Feb-76 obv.jpg|thumb|220px|right|Continental One Third Dollar Bill (obverse)]]
In 1775, the United States and the individual states began issuing "Continental Currency" denominated in Spanish dollars and (for the issues of the states) the £sd currencies of the states. The dollar was valued relative to the states' currencies at the following rates:

{|class="wikitable"
|-
! style="width:450pt;"|State
!Value of Dollar<br />in State Currency
|-
|[[Georgia (U.S. state)|Georgia]]
|align=center|5 Shillings
|-
|[[Connecticut]], [[Massachusetts]], [[New Hampshire]], [[Rhode Island]], [[Virginia]]
|align=center|6 Shillings
|-
|[[Delaware]], [[Maryland]], [[New Jersey]], [[Pennsylvania]]
|align=center|7½ Shillings
|-
|New York, [[North Carolina]]
|align=center|8 Shillings
|-
|[[South Carolina]]
|align=center|32½ Shillings
|}

The continental currency suffered from printing press inflation and was replaced by the silver dollar at the rate of 1 silver dollar = 1000 continental dollars.

===Silver and gold standards===
{{Unreferenced section|date=April 2010}}
From 1792, when the [[Mint Act]] was passed, the dollar was defined as 371.25 [[grain (unit)|grains]] (24.056 g) of silver. Many historians{{Who|date=February 2009}} erroneously assume gold was standardized at a fixed rate in parity with silver; however, there is no evidence of Congress making this law. This has to do with [[Alexander Hamilton]]'s suggestion to Congress of a fixed 15:1 ratio of silver to gold, respectively. The gold coins that were minted however, were not given any denomination whatsoever and traded for a market value relative to the Congressional standard of the silver dollar. 1834 saw a shift in the [[gold standard]] to {{convert|23.2|gr}}, followed by a slight adjustment to {{convert|23.22|gr}} in 1837 (16:1 ratio).{{Citation needed|date=October 2007}}

In 1862, paper money was issued without the backing of precious metals, due to the [[American Civil War|Civil War]]. Silver and gold coins continued to be issued and in 1878 the link between paper money and coins was reinstated. This disconnection from gold and silver backing also occurred during the [[War of 1812]]. The use of paper money not backed by precious metals had also occurred under the Articles of Confederation from 1777 to 1788. With no solid backing and being easily counterfeited, the continentals quickly lost their value, giving rise to the phrase "not worth a continental". This was a primary reason for the "No state shall... make any thing but gold and silver coin a tender in payment of debts" clause in [[Article One of the United States Constitution#Section 10: Limits on the States|article 1, section 10]] of the United States Constitution.

The [[Gold Standard Act]] of 1900 abandoned the bimetallic standard and defined the dollar as {{convert|23.22|gr}} of gold, equivalent to setting the price of 1 [[troy ounce]] of gold at $20.67. Silver coins continued to be issued for circulation until 1964, when all silver was removed from dimes and quarters, and the half dollar was reduced to 40% silver. Silver half dollars were last issued for circulation in 1970. Gold coins were confiscated by [[Executive Order 6102]] issued in 1933 by Franklin Roosevelt. The gold standard was changed to {{convert|13.71|gr}}, equivalent to setting the price of 1 troy ounce of gold at $35. This standard persisted until 1968.

Between 1968 and 1975, a variety of pegs to gold were put in place, eventually culminating in a sudden end, on August 15, 1971 to the convertibility of dollars to gold later dubbed the [[Nixon Shock]]. The last peg was $42.22 per ounce{{Citation needed|date=October 2007}} before the U.S. dollar was let to freely float on [[Foreign exchange market|currency markets]].

According to the [[Bureau of Engraving and Printing]], the largest note it ever printed was the $100,000 Gold Certificate, Series 1934. These notes were printed from December 18, 1934 through January 9, 1935, and were issued by the Treasurer of the United States to Federal Reserve Banks only against an equal amount of gold bullion held by the Treasury. These notes were used for transactions between Federal Reserve Banks and were not circulated among the general public.

==Coins==
{{Main|Coins of the United States dollar}}

Official United States coins have been produced every year from 1792 to the present.

* [[Half cent (United States coin)|Half-cent]] 1792–1857
* [[Penny (United States coin)|Cent (Penny)]] 1793–present
* [[Two-cent piece (United States coin)|2-cent]] 1864–1873
* [[Three-cent piece (United States coin)|3-cent]] 1851–1889
* [[Half Dime]], or half disme 1792–1873 (Not to be confused with the Five-cent Nickel below)
* [[Nickel (United States coin)|Five-cent Nickel]] 1866–present
* [[Dime (United States coin)|Dime]] 1792–present
* [[Twenty-cent piece (United States coin)|20-cent]] 1875–1878
* [[Quarter (United States coin)|Quarter]] 1796–present
* [[Half dollar (United States coin)|Half dollar]] 1794–present
* [[Dollar coin (United States)|Dollar coin]] 1794–present
* [[Quarter Eagle]] ($2.50 gold coin) 1792–1929
* [[Three-dollar piece]] 1854–1889 (gold coin)
* [[Stella (United States coin)|Four-dollar piece]]  1879–1880 (gold coin)
* [[Half Eagle]] ($5 gold coin) 1795–1929
* [[Eagle (United States coin)|Eagle]] ($10 gold coin) 1795–1933
* [[Double Eagle]] ($20 gold coin) 1850–1933

'''Collector coins''' for which everyday transactions are non-existent.<ref>{{cite web|url=http://beyondmoney.net/2007/11/08/irs-court-case-shakes-the-foundations-of-the-debt-money-system/ |title=IRS Court Case Shakes the Foundations of the Debt Money System |publisher=Beyondmoney.net |date=November 8, 2007 |accessdate=August 24, 2010}}</ref>

* [[American Eagle bullion coins|American Eagles]] originally were not available from the Mint for individuals but had to be purchased from authorized dealers. In 2006 The Mint began direct sales to individuals of uncirculated bullion coins with a special finish, and bearing a "W" mintmark.
** [[American Silver Eagle]] $1 (1 [[troy ounce]]) silver bullion coin 1986–present
** [[American Gold Eagle]] $5 (1/10 troy oz), $10 (1/4 troy oz), $25 (1/2 troy oz), and $50 (1 troy oz) Gold bullion coin 1986–present
** [[American Platinum Eagle]] ($10, $25, $50, and $100 platinum coin) 1997–present

* [[United States commemorative coin]]s—special issue coins
** [[Half union|$50.00 (Half Union)]] 1915
** Presidential Proofs (see below) 2007–present

Technically, all these coins are still legal tender at face value, though some are far more valuable today for their [[numismatics|numismatic]] value, and for gold and silver coins, their [[precious metal]] value.  From 1965 to 1970 the [[Kennedy half dollar]] was the only ''circulating'' coin with any silver content though the Mint still makes what it calls Silver Proof sets for collectors.

In addition, an experimental [[Stella (United States coin)|$4.00 (Stella)]] coin was also minted, but never placed into circulation and is properly considered to be a pattern rather than an actual coin denomination.

The $50 coin mentioned was only produced in 1915 for the [[Panama-Pacific International Exposition (1915)]] celebrating the opening of the [[Panama Canal]]. Only 1,128 were made, 645 of which were octagonal; this remains the only U.S. coin that was not round as well as the largest and heaviest U.S. coin ever.

From 1934 to present the only denominations produced for circulation have been the familiar penny, nickel, dime, quarter, half dollar and dollar. The nickel is the only coin still in use today that is essentially unchanged (except in its design) from its original version. Every year since 1866, the nickel has been 75% copper and 25% nickel, except for 4 years during [[World War II]] when nickel was needed for the war.

===Collector coins===
The United States Mint produces Proof Sets specifically for collectors and speculators.  ''Silver Proofs'' tend to be the standard designs but with the dime, quarter, half dollar, and in some cases the dollar having silver content.  Another type of proof set is the Presidential Dollar Proof Set where four special $1 coins are minted each year featuring a president.

Until 2012, the United States Mint intended for the presidential coins to be used in circulation, but in 2012, the mint only made them for collectors to save money.

* 2007 had George Washington, John Adams, Thomas Jefferson, and James Madison
* 2008 had James Monroe, John Quincy Adams, Andrew Jackson, and Martin Van Buren
* 2009 had William Henry Harrison, John Tyler, James K. Polk, and Zachary Taylor
* 2010 had Millard Fillmore, Franklin Pierce, James Buchanan, and Abraham Lincoln
* 2011 had Andrew Johnson, Ulysses S. Grant, Rutherford B. Hayes, and James A. Garfield
* 2012 had Chester Arthur, Grover Cleveland (1st term), Benjamin Harrison, and Grover Cleveland (2nd term)
* 2013 will have William McKinley, Theodore Roosevelt, William Howard Taft and Woodrow Wilson
* 2014 will have Warren G. Harding, Calvin Coolidge, Herbert Hoover, and Franklin D. Roosevelt
* 2015 will have Harry S Truman, Dwight D. Eisenhower, John F. Kennedy, and Lyndon B. Johnson
* 2016 will have Richard M. Nixon, Gerald R. Ford, and Ronald W. Reagan

===Dollar coins===
{{Off-topic|Coins of the United States dollar|date=April 2010}}
[[File:Аверс доллара с изображением Свободы с распущенными волосами.jpg|200px|thumb|[[Flowing Hair Dollar]]]]
The first United States dollar was minted in 1794. Known as the [[Flowing Hair Dollar]], it contained 416 [[Grain (mass)|grains]] of "standard silver" (89.25% silver and 10.75% copper), as specified by Section 13<ref>{{cite web|url=http://memory.loc.gov/cgi-bin/ampage?collId=llsl&fileName=001/llsl001.db&recNum=372 |title=Section 13 of the Coinage Act of 1792 |publisher=Memory.loc.gov |accessdate=August 24, 2010}}</ref> of the [[Coinage Act of 1792]]. It was designated by Section 9 of that Act as having "the value of a [[Spanish milled dollar]]".

[[Dollar (United States coin)|Dollar coins]] have not been very popular in the United States.<ref>CNN Money [http://money.cnn.com/2005/04/27/pf/new_dollar/ ''Congress tries again for a dollar coin'']. Written by Gordon T. Anderson. Published April 25, 2005.</ref>  [[United States dollar coin|Silver dollars]] were minted intermittently from 1794 through 1935; a copper-nickel dollar of the same large size, featuring President [[Dwight D. Eisenhower]], was minted from 1971 through 1978. Gold dollars were also minted in the 19th century. The [[Susan B. Anthony]] [[Susan B. Anthony dollar|dollar]] coin was introduced in 1979; these proved to be unpopular because they were often mistaken for quarters, due to their nearly equal size, their milled edge, and their similar color. Minting of these dollars for circulation was suspended in 1980 (collectors' pieces were struck in 1981), but, as with all past U.S. coins, they remain [[legal tender]]. As the number of Anthony dollars held by the Federal Reserve and dispensed primarily to make change in postal and transit vending machines had been virtually exhausted, additional Anthony dollars were struck in 1999. In 2000, a new $1 coin, featuring [[Sacagawea]], (the [[Sacagawea dollar]]) was introduced, which corrected some of the mistakes of the Anthony dollar by having a smooth edge and a gold color, without requiring changes to vending machines that accept the Anthony dollar. However, this new coin has failed to achieve the popularity of the still-existing $1 bill and is rarely used in daily transactions. The failure to simultaneously withdraw the dollar bill and weak publicity efforts have been cited by coin proponents as primary reasons for the failure of the dollar coin to gain popular support.<ref>{{cite web|url=http://www.gao.gov/new.items/d02896.pdf |title=Report to the Subcommittee on Treasury and General Government, Committee on Appropriations, U.S. Senate |publisher=USGAO |date= |accessdate=2013-05-05}}</ref>

In February 2007, the [[U.S. Mint]], under the [[Presidential $1 Coin Act of 2005]],<ref>Pub. L. No. 109-145, 119 Stat. 2664 (December 22, 2005).</ref> introduced a new $1 U.S. Presidential dollar coin. Based on the success of the "[[50 State Quarters]]" series, the new coin features a sequence of presidents in order of their inaugurations, starting with [[George Washington]], on the obverse side. The reverse side features the [[Statue of Liberty]]. To allow for larger, more detailed portraits, the traditional inscriptions of "[[E Pluribus Unum]]", "[[In God We Trust]]", the year of minting or issuance, and the mint mark will be inscribed on the edge of the coin instead of the face. This feature, similar to the edge inscriptions seen on the [[One pound (British decimal coin)|British £1]] coin, is not usually associated with U.S. coin designs. The inscription "Liberty" has been eliminated, with the Statue of Liberty serving as a sufficient replacement. In addition, due to the nature of U.S. coins, this will be the first time there will be circulating U.S. coins of different denominations with the same president featured on the obverse (heads) side ([[Abraham Lincoln|Lincoln]]/[[Cent (United States coin)|penny]], [[Thomas Jefferson|Jefferson]]/[[Nickel (United States coin)|nickel]], [[Franklin D. Roosevelt]]/[[Dime (United States coin)|dime]], [[George Washington|Washington]]/[[Quarter (United States coin)|quarter]], [[John F. Kennedy|Kennedy]]/[[Half dollar (United States coin)|half dollar]], and [[Dwight D. Eisenhower|Eisenhower]]/[[Dollar (United States coin)|dollar]]). Another unusual fact about the new $1 coin is [[Grover Cleveland]] will have two coins with his portrait issued due to the fact he was the only U.S. President to be elected to two non-consecutive terms.<ref>{{cite web|author=The United States Mint |url=http://www.usmint.com/pressroom/index.cfm?action=press_release&ID=722 |title=The United States Mint Pressroom |publisher=Usmint.com |accessdate=August 24, 2010}}</ref>

Early releases of the Washington coin included [[error coins]] shipped primarily from the Philadelphia mint to Florida and Tennessee banks.  Highly sought after by collectors, and trading for as much as $850 each within a week of discovery, the error coins were identified by the absence of the edge impressions "E PLURIBUS UNUM IN GOD WE TRUST 2007 P".  The mint of origin is generally accepted to be mostly Philadelphia, although identifying the source mint is impossible without opening a mint pack also containing marked units.  Edge lettering is minted in both orientations with respect to "heads", some amateur collectors were initially duped into buying "upside down lettering error" coins.<ref>[http://ap.washingtontimes.com/dynamic/stories/G/GODLESS_DOLLARS Godless Dollars]</ref> Some cynics also erroneously point out that the Federal Reserve makes more profit from dollar bills than dollar coins because they wear out in a few years, whereas coins are more permanent. The fallacy of this argument arises because new notes printed to replace worn out notes, which have been withdrawn from circulation bring in no net revenue to the government to offset the costs of printing new notes and destroying the old ones. As most [[vending machines]] are incapable of making change in [[banknotes]], they commonly accept only $1 bills, though a few will give change in dollar coins.

===Mint marks===
{| class="wikitable'
|-
!Mint
!Mint mark
!Metal Minted
!Year Established
!Current Status
|-
| Denver
| D
| All metals
| 1906
| Still in operation
|-
| Philadelphia 
| None, see note 1
| 
| 1792
| Still in operation
|-
| San Francisco
| S
| All metals
| 1854
| Still in operation (proof coins, only)
|-
| New Orleans
| O
| Gold and Silver
| 1838
| Closed in 1861, reopened in 1879, closed in 1909, see note 2
|-
| Carson City
| CC
| Gold and Silver
| 1870
| Closed in 1893, see note 3
|-
| Dahlonega
| D see note 4
| Gold only
| 1838
| Closed in 1861
|-
| Charlotte
| C
| Gold only
| 1838
| Closed in 1861
|-
| West Point
| W see note 5
| Gold, Silver and Platinum
| 1973
| Still in operation
|}

Note 1:  From 1942 to 1945 the letter "P" was used for the Philadelphia mint mark on Jefferson nickels (using the silver content), from 1980 on the letter "P" was used for the Philidelphea mint mark on a permanent basis.

Note 2:  During the Civil War, this mint operated under the control of the State of Louisiana (February, 1861) and the Confederate States of America (March, 1861) until it ran out of bullion later in that year; some Half Dollars have been identified as being the issue of the State of Louisiana and the Confederacy.

Note 3:  Press Number 1 is still in use by the Nevada State Museum; it produces tokens for the Reno Coin Club.

Note 4:  Although the mint mark "D" is used for two separate mints, it is easy to distinguish between the two; any antibellum coinage (up to 1861) is Dahlonega, and any 20th century or later coinage is Denver.

Note 5:  Between 1973 and 1986 there was no mint mark; these coins are indistinguishable from coins produced at the Philadelphia Mint (note 1 notwithstanding): after 1988 the letter "W" was used for coinage (except for the 2009 Ultra High Relief Double Eagle)

==Banknotes==
{{Main|Federal Reserve Note}}
{| class="wikitable"
|- style="background:#2E8B57;"
! Denomination
! Obverse
! Reverse
! Portrait
! First Series
! Latest Series
|-
| 1 Dollar
| [[File:United States one dollar bill, obverse.jpg|250px]]
| [[File:United States one dollar bill, reverse.jpg|250px]]
| [[George Washington]]
| Series 1963
| Series 2009
|-
| 2 Dollars
| [[File:US $2 obverse.jpg|250px]]
| [[File:US $2 reverse.jpg|250px]]
| [[Thomas Jefferson]]
| Series 1976
| Series 2009
|-
| 5 Dollars
| [[File:US $5 Series 2006 obverse.jpg|250px]]
| [[File:US $5 Series 2006 reverse.jpg|250px]]
| [[Abraham Lincoln]]
| Series 2006
| Series 2013
|-
| 10 Dollars
| [[File:US10dollarbill-Series 2004A.jpg|250px]]
| [[File:US $10 Series 2004 reverse.jpg|250px]]
| [[Alexander Hamilton]]
| Series 2004A
| Series 2009
|-
| 20 Dollars
| [[File:US20-front.jpg|250px]]
| [[File:US20-back.jpg|250px]]
| [[Andrew Jackson]]
| Series 2004
| Series 2009
|-
| 50 Dollars
| [[File:Series2004NoteFront 50.jpg|250px]]
| [[File:Series2004NoteBack 50.jpg|250px]]
| [[Ulysses S. Grant]]
| Series 2004
| Series 2009
|-
| 100 Dollars
| [[File:New100front.jpg|250px]]
| [[File:New100back.jpg|250px]]
| [[Benjamin Franklin]]
| Series 2009
| Series 2009A
|}

The U.S. Constitution provides that Congress shall have the power to "borrow money on the credit of the United States".<ref>{{cite web|url=http://topics.law.cornell.edu/constitution/articlei#section8 |title=Paragraph 2 of Section 8 of Article 1 of the United States Constitution |publisher=Topics.law.cornell.edu |accessdate=August 24, 2010}}</ref> Congress has exercised that power by authorizing [[Federal Reserve Banks]] to issue [[Federal Reserve Notes]]. Those notes are "obligations of the United States" and "shall be redeemed in lawful money on demand at the Treasury Department of the United States, in the city of Washington, District of Columbia, or at any Federal Reserve bank."<ref>{{cite web|url=http://www.law.cornell.edu/uscode/12/411.html |title=Section 411 of Title 12 of the United States Code |publisher=Law.cornell.edu |date=June 22, 2010 |accessdate=August 24, 2010}}</ref> Federal Reserve Notes are designated by law as "[[legal tender]]" for the payment of debts.<ref>{{cite web|url=http://www.law.cornell.edu/uscode/html/uscode31/usc_sec_31_00005103----000-.html |title=Section 5103 of Title 31 of the United States Code |publisher=Law.cornell.edu |date=August 6, 2010 |accessdate=August 24, 2010}}</ref> Congress has also authorized the issuance of more than 10 other types of banknotes, including the [[United States Note]]<ref>{{cite web|url=http://www.law.cornell.edu/uscode/html/uscode31/usc_sec_31_00005115----000-.html |title=Section 5115 of Title 31 of the United States Code |publisher=Law.cornell.edu |date=August 6, 2010 |accessdate=August 24, 2010}}</ref> and the [[Federal Reserve Bank Note]]. The Federal Reserve Note is the only type that remains in circulation since the 1970s.

Currently printed denominations are [[United States one-dollar bill|$1]], [[United States two-dollar bill|$2]], [[United States five-dollar bill|$5]], [[United States ten-dollar bill|$10]], [[United States twenty-dollar bill|$20]], [[United States fifty-dollar bill|$50]], and [[United States one hundred-dollar bill|$100]]. Notes above the $100 denomination stopped being printed in 1946 and were officially withdrawn from circulation in 1969. These notes were used primarily in inter-bank transactions or by [[organized crime]]; it was the latter usage that prompted President [[Richard Nixon]] to issue an executive order in 1969 halting their use. With the advent of electronic banking, they became less necessary. Notes in denominations of $500, $1,000, $5,000, $10,000 and $100,000 were all produced at one time; see [[large denomination bills in U.S. currency]] for details. These notes are now collectors' items and are worth more than their face value to collectors.

Though still predominantly green, post-2004 series incorporate other colors to better distinguish different denominations.  As a result of a 2008 decision in an accessibility lawsuit filed by the [[American Council of the Blind]], the [[Bureau of Engraving and Printing]] is planning to implement a raised tactile feature in the next redesign of each note, except the $1 and the version of the $100 bill already in process.  It also plans larger, higher-contrast numerals, more color differences, and distribution of currency readers to assist the visually impaired during the transition period.<ref>See [[Federal Reserve Note]] for details and references</ref>

==Means of issue==

The monetary base consists of coins and Federal Reserve Notes in circulation outside the Federal Reserve Banks and the U.S. Treasury, plus deposits held by depository institutions at Federal Reserve Banks. The adjusted monetary base has increased from approximately 400 billion dollars in 1994, to 800 billion in 2005, and over 3000 billion in 2013.<ref>{{cite web | url=http://research.stlouisfed.org/fred2/series/BASE/ | title=St. Louis Adjusted Monetary Base | publisher=[[Federal Reserve Bank of St. Louis]] | accessdate=2013-05-03}}</ref> The amount of cash in circulation is increased (or decreased) by the actions of the [[Federal Reserve System]]. Eight times a year, the 12-person [[Federal Open Market Committee]] meet to determine US [[monetary policy]].<ref>{{cite web |publisher=The Federal Reserve Bank of Minneapolis |title=The Federal Reserve's Beige Book |url=http://minneapolisfed.org/pubs/region/99-03/beige.cfm |accessdate=January 6, 2008 }}</ref>  Every business day, the Federal Reserve System engages in [[Open market operations]] to carry out that monetary policy.<ref>{{cite web |first=Phil |last=Davies |title=Right on Target |url=http://minneapolisfed.org/pubs/region/04-12/davies.cfm |quote=Federal Reserve Bank of Minneapolis |accessdate=January 7, 2008 }}</ref> If the Federal Reserve desires to increase the money supply, it will buy securities (such as US Treasury Bonds) anonymously from banks in exchange for dollars. Conversely, it will sell securities to the banks in exchange for dollars, to take dollars out of circulation.<ref name="newyorkfed.org">{{cite web |title=Open Market Operations |publisher=Federal Reserve Bank of Mew York |url=http://www.newyorkfed.org/aboutthefed/fedpoint/fed32.html |quote=Open market operations enable the Federal Reserve to affect the supply of reserve balances in the banking system. |accessdate=January 11, 2008 }}</ref>

When the Federal Reserve makes a purchase, it credits the seller's reserve account (with the Federal Reserve).  This money is not transferred from any existing funds—it is at this point that the Federal Reserve has created new [[high-powered money]]. Commercial banks can freely withdraw in cash any excess reserves from their reserve account at the Federal Reserve.  To fulfill those requests, the Federal Reserve places an order for printed money from the US Treasury Department.<ref>{{cite web |title=Fact Sheets: Currency & Coins |publisher=United States Department of the Treasury |url=http://www.treas.gov/education/fact-sheets/currency/distribution.shtml |accessdate=January 22, 2008 }}</ref>  The Treasury Department in turn sends these requests to the Bureau of Engraving and Printing (to print new [[Federal Reserve notes|dollar bills]]) and the Bureau of the Mint (to stamp the coins).

Usually, the short term goal of open market operations is to achieve a specific short term interest rate target. In other instances, monetary policy might instead entail the targeting of a specific exchange rate relative to some foreign currency or else relative to gold. For example, in the case of the United States the Federal Reserve targets the [[federal funds rate]], the rate at which member banks lend to one another overnight. The other primary means of conducting monetary policy include: (i) [[Discount window]] lending (as [[lender of last resort]]); (ii) Fractional deposit lending (changes in the reserve requirement); (iii) Moral suasion (cajoling certain market players to achieve specified outcomes); (iv) "Open mouth operations" (talking monetary policy with the market).

==Value==

{| cellspacing="0" cellpadding="0" style="float:right; clear:right; margin:0 0 0 1em;"
|+ '''Buying power of one U.S. dollar compared to 1774 USD'''
|- valign="top"
|
{| class="wikitable" style="margin:0;"
|-
!&nbsp;Year&nbsp;
!style="width: 40pt; font-size: 95%;"|&nbsp;Equivalent&nbsp; buying power
|-
|1774||&nbsp;$1.00
|-
|1780||&nbsp;$0.59
|-
|1790||&nbsp;$0.89
|-
|1800||&nbsp;$0.64
|-
|1810||&nbsp;$0.66
|-
|1820||&nbsp;$0.69
|-
|1830||&nbsp;$0.88
|-
|1840||&nbsp;$0.94
|-
|1850||&nbsp;$1.03
|-
|1860||&nbsp;$0.97
|}
|
{| class="wikitable" style="margin:0;"
|-
!&nbsp;Year&nbsp;
!style="width: 40pt; font-size: 95%;"|&nbsp;Equivalent&nbsp; buying power
|-
|1870||&nbsp;$0.62
|-
|1880||&nbsp;$0.79
|-
|1890||&nbsp;$0.89
|-
|1900||&nbsp;$0.96
|-
|1910||&nbsp;$0.85
|-
|1920||&nbsp;$0.39
|-
|1930||&nbsp;$0.47
|-
|1940||&nbsp;$0.56
|-
|1950||&nbsp;$0.33
|-
|1960||&nbsp;$0.26
|}
|
{| class="wikitable" style="margin:0;"
|-
!&nbsp;Year&nbsp;
!style="width: 40pt; font-size: 95%;"|&nbsp;Equivalent&nbsp; buying power
|-
|1970||&nbsp;$0.20
|-
|1980||&nbsp;$0.10
|-
|1990||&nbsp;$0.06
|-
|2000||&nbsp;$0.05
|-
|2007||&nbsp;$0.04
|-
|2008||&nbsp;$0.04
|-
|2009||&nbsp;$0.04
|-
|2010||&nbsp;$0.035
|-
|2011||&nbsp;$0.034
|-
|2012||&nbsp;$0.03
|}
|}
[[File:US Consumer Price Index Graph.svg|thumb|460px|U.S. Consumer Price Index 1913–2006]]

The 6th paragraph of [[Coinage clause|Section 8]] of Article 1 of the U.S. Constitution provides that the U.S. Congress shall have the power to "coin money" and to "regulate the value" of domestic and foreign coins. Congress exercised those powers when it enacted the [[Coinage Act of 1792]]. That Act provided for the minting of the [[Flowing Hair Dollar|first U.S. dollar]] and it declared that the U.S. dollar shall have "the value of a [[Spanish milled dollar]] as the same is now current".<ref>{{cite web|url=http://memory.loc.gov/cgi-bin/ampage?collId=llsl&fileName=001/llsl001.db&recNum=371 |title=Section 9 of the Coinage Act of 1792 |publisher=Memory.loc.gov |accessdate=August 24, 2010}}</ref>

The table to the right shows the equivalent amount of goods that, in a particular year, could be purchased with $1. The table shows that from 1774 through 2012 the U.S. dollar has lost about 97.0% of its buying power.<ref name="measuring-worth">{{cite web| title = Measuring Worth – Purchasing Power of Money in the United States from 1774 to 2010 | url=http://www.measuringworth.com/ppowerus/ | accessdate =April 22, 2010}}</ref>

The decline in the value of the U.S. dollar corresponds to [[price inflation]], which is a rise in the general level of prices of goods and services in an economy over a period of time.<ref>[[Oliver Blanchard]] (2000). ''Macroeconomics'' (2nd ed.), Englewood Cliffs, N.J: Prentice Hall, ISBN 0-13-013306-X</ref> A [[consumer price index]] (CPI) is a measure estimating the average price of consumer goods and services purchased by households.  The [[United States Consumer Price Index]], published by the [[Bureau of Labor Statistics]], is a measure estimating the average price of consumer goods and services in the United States.<ref>{{cite web| title = Consumer Price Index Frequently Asked Questions | url=http://www.bls.gov/cpi/cpifaq.htm#Question_1 | accessdate =July 17, 2010 }}</ref> It reflects inflation as experienced by consumers in their day-to-day living expenses.<ref>{{cite web| title = Consumer Price Index Frequently Asked Questions | url=http://www.bls.gov/cpi/cpifaq.htm#Question_12 | accessdate =July 17, 2010 }}</ref> A graph showing the U.S. CPI relative to 1982–1984 and the annual year-over-year change in CPI is shown at right.

The value of the U.S. dollar declined significantly during wartime, especially during the [[American Civil War]], World War I, and World War II.<ref>{{cite book | title = [[A Monetary History of the United States|A monetary history of the United States, 1867–1960]] | author = [[Milton Friedman]], [[Anna Jacobson Schwartz]] | isbn=B000OL2K26 | page=546 }}</ref> The [[Federal Reserve]], which was established in 1913, was designed to furnish an "elastic" currency subject to "substantial changes of quantity over short periods," which differed significantly from previous forms of [[high-powered money]] such as gold, national bank notes, and silver coins.<ref>Friedman 189–190</ref> Over the very long run, the prior gold standard kept prices stable—for instance, the price level and the value of the U.S. dollar in 1914 was not very different from the price level in the 1880s. The Federal Reserve initially succeeded in maintaining the value of the U.S. dollar and price stability, reversing the inflation caused by the First World War and stabilizing the value of the dollar during the 1920s, before presiding over a 30% deflation in U.S. prices in the 1930s.<ref name="central-banking-then-and-now">{{cite web | url = http://www.minneapolisfed.org/publications_papers/pub_display.cfm?id=3723 | title = Central Banking—Then and Now | accessdate=July 17, 2010 }}</ref>

Under the [[Bretton Woods system]] established after World War II, the value of gold was fixed to $35 per ounce, and the value of the U.S. dollar was thus anchored to the value of gold. Rising government spending in the 1960s, however, led to doubts about the ability of the United States to maintain this convertibility, gold stocks dwindled as banks and international investors began to convert dollars to gold, and as a result the value of the dollar began to decline. Facing an emerging [[currency crisis]] and the imminent danger that the United States would no longer be able to redeem dollars for gold, gold convertibility was finally terminated in 1971 by [[Richard Nixon|President Nixon]], resulting in the "[[Nixon shock]]."<ref name="inflation-historical-perspective">{{cite web | url = http://www.dallasfed.org/research/swe/1993/swe9304b.pdf | title = Controlling Inflation: A Historical Perspective | accessdate=July 17, 2010 }}</ref>

The value of the U.S. dollar was therefore no longer anchored to gold, and it fell upon the Federal Reserve to maintain the value of the U.S. currency. The Federal Reserve, however, continued to increase the money supply, resulting in [[stagflation]] and a rapidly declining value of the U.S. dollar in the 1970s. This was largely due to the prevailing economic view at the time that inflation and real economic growth were linked (the [[Phillips curve]]), and so inflation was regarded as relatively benign.<ref name="inflation-historical-perspective"/> Between 1965 and 1981, the U.S. dollar lost two thirds of its value.<ref name="measuring-worth"/>

In 1979, [[Jimmy Carter|President Carter]] appointed [[Paul Volcker]] [[Chairman of the Federal Reserve]]. The Federal Reserve tightened the money supply and inflation was substantially lower in the 1980s, and hence the value of the U.S. dollar stabilized.<ref name="inflation-historical-perspective"/>

Over the thirty-year period from 1981 to 2009, the U.S. dollar lost over half its value.<ref name="measuring-worth"/> This is because the Federal Reserve has targeted not zero inflation, but a low, stable rate of inflation—between 1987 and 1997, the rate of inflation was approximately 3.5%, and between 1997 and 2007 it was approximately 2%. The so-called "[[Great Moderation]]" of economic conditions since the 1970s is credited to monetary policy targeting price stability.<ref name="inflation-historical-perspective">{{cite web | url = http://www.federalreserve.gov/boarddocs/speeches/2005/20051103/default.htm | title = Monetary Credibility, Inflation, and Economic Growth | accessdate=July 17, 2010 }}</ref>

There is ongoing debate about whether central banks should target zero inflation (which would mean a constant value for the U.S. dollar over time) or low, stable inflation (which would mean a continuously but slowly declining value of the dollar over time, as is the case now). Although some economists are in favor of a zero inflation policy and therefore a constant value for the U.S. dollar,<ref name="central-banking-then-and-now"/> others contend that such a policy limits the ability of the central bank to control [[interest rates]] and stimulate the economy when needed.<ref>{{cite web | url = http://www.frbsf.org/publications/federalreserve/monetary/goals.html | title = U.S. Monetary Policy: The Fed's Goals | accessdate=July 17, 2010 }}</ref>

==Exchange rates==

===Historical exchange rates===
<!-- Please double check my work for accuracy. Once someone certifies this, please remove this note.
     Note: this is a table of AVERAGE exchange rates.  Please do not add rates for the current year, as there has to be data from the whole year in order to have a valid average.
 -->
{|class="wikitable"
|+ Currency units per U.S. dollar, averaged over the year.<ref>{{cite web|url=http://www.federalreserve.gov/releases/g5a/ |title=FRB: G.5A Release- Foreign Exchange Rates, Release Dates |publisher=Federalreserve.gov |accessdate=August 24, 2010}}</ref> * = value at start of year.
! !! 1970* !! 1980* || 1985* !! 1990* !! 1993 !! 1999  !!  2000  !!  2001  !!  2002  !!  2003  !!  2004  !!  2005  !!  2006  !!  2007 !! 2008 !! 2009 !! 2010 !! 2011 !! 2012 !! 2013
|-
| [[Euro]]* || — || — || — || 0.6571 || 0.6734 || 0.9387 || 1.0832 || 1.1171 || 1.0578 || 0.8833 || 0.8040 || 0.8033 || 0.7960 || 0.7293 || 0.6791 || 0.7176 || 0.6739 || 0.7178 || 0.7777
|-
| [[Japanese yen]] || 357.6 || 240.45 || 250.35 || 146.25 || 111.08 || 113.73 || 107.80 || 121.57 || 125.22 || 115.94 || 108.15 || 110.11 || 116.31 || 117.76 || 103.39 || 93.68 || 87.78 || 79.70 || 79.82 
|-
| [[Pound sterling]] || 8[[Shilling (British coin)|s]]&nbsp;4[[Penny (British pre-decimal coin)|d]]<br>=0.4167 || 0.4484<ref name="austats">[http://www.rba.gov.au/Statistics/HistoricalExchangeRates/index.html 1970–1992]. 1980 derived from AUD-USD=1.1055 and AUD-GBP=0.4957 at end of Dec 1979: 0.4957/1.1055=0.448394392; 1985 derived from AUD-USD=0.8278 and AUD-GBP=0.7130 at end of Dec 1984: 0.7130/0.8278=0.861319159</ref> || 0.8613<ref name="austats"/> || 0.6207 || 0.6660 || 0.6184 || 0.6598 || 0.6946 || 0.6656 || 0.6117 || 0.5456 || 0.5493 || 0.5425 || 0.4995 || 0.5392 || 0.6385 || 0.4548 || 0.6233 || 0.6308 
|-
| [[Canadian dollar]] || 1.081 || 1.168 || 1.321 || 1.1605 || 1.2902 || 1.4858 || 1.4855 || 1.5487 || 1.5704 || 1.4008 || 1.3017 || 1.2115 || 1.1340 || 1.0734 || 1.0660 || 1.1412 || 1.0298 || 0.9887 ||  
|-
| [[Mexican peso]]|| 0.01250 - 0.02650<sup>1</sup> || 2.80<sup>1</sup> || 2.67<sup>1</sup> || 2.50<sup>1</sup> || 3.1237 || 9.553 || 9.459  || 9.337 ||  9.663 || 10.793 || 11.290 || 10.894 || 10.906 || 10.928 || 11.143 || 13.498 || 12.623 || 12.427 || 
|-
| [[Renminbi yuan]]|| 2.46 || 1.7050 || 2.9366 || 4.7832 || 5.7620 || 8.2783 || 8.2784 || 8.2770 || 8.2771 || 8.2772 || 8.2768 || 8.1936 || 7.9723 || 7.6058 || 6.9477 || 6.8307 || 6.7696 || 6.4630 ||
|-
| [[Indian rupee]]|| – || 8.000 || 12.38 || 16.96 || 31.291 || 43.13 || 45.00 || 47.22 || 48.63 || 46.59 || 45.26 || 44.00 || 45.19 || 41.18 || 43.39 || 48.33 || 45.65 || 46.58 || 54.08 || 65
|-
| [[Singapore dollar]] || — || — || 2.179 || 1.903 || 1.6158 || 1.6951 || 1.7361  || 1.7930  ||  1.7908 || 1.7429 || 1.6902 || 1.6639 || 1.5882 || 1.5065 || 1.4140 || 1.4543 || 1.24586 || 1.2565 ||
|-
| [[South African Rand]] || 0.7182 || 0.7780 || 2.2343<ref name="SAmeasuringW">{{cite web | url=http://www.measuringworth.com/datasets/exchangeglobal/result.php | title=Exchange Rates Between the United States Dollar and the South African Rand | publisher=Measuring Worth | accessdate=December 5, 2011}}</ref> ||2.5600 || 3.2729 ||6.1191 || 6.9468 || 8.6093 || 10.5176 || 7.5550 ||6.4402 ||6.3606 || 6.7668 ||7.0477 ||8.2480 || 8.4117 || 7.3159 || 7.2510 || 
|-   
|colspan="18" |<sub>Source: [http://www.federalreserve.gov/releases/g5a/current/ Last 4 years] [http://www.federalreserve.gov/releases/g5a/20060103/ 2005-2002] [http://www.federalreserve.gov/releases/g5a/20040102/ 2003–2000] [http://www.federalreserve.gov/releases/g5a/20000103/ 1996–1999] [http://www.federalreserve.gov/releases/g5a/19970107/ 1993–1996] [http://www.x-rates.com/cgi-bin/hlookup.cgi 1990] [http://www.rba.gov.au/Statistics/HistoricalExchangeRates/index.html 1970–1992] [http://intl.econ.cuhk.edu.hk/exchange_rate_regime/index.php?cid=8 1970–1985 Canada, China, Mexico]<br />
1. Mexican peso values prior to 1993 revaluation.
2. Before 1999 use Irish pound
|}

=== Current exchange rates ===
{{Exchange Rate|USD|RUB|INR|CNY|TWD|KRW|style=navbox}}

==See also==
{{Portal|Government of the United States|Numismatics}}
* [[Federal Reserve Note]]
* [[US coin]]
* [[Counterfeit United States currency]]
* [[International use of the US dollar]]
* [[Strong dollar policy]]
* [[Series (United States currency)]]
{{-}}

==References==
{{Reflist|colwidth=30em}}

==External links==
{{Commons|United States dollar}}
* [http://www.moneyfactory.gov/ U.S. Bureau of Engraving and Printing]
* [http://www.fms.treas.gov/bulletin/ U.S. Currency and Coin Outstanding and in Circulation]
* [http://www.newmoney.gov/currency/images.htm U.S. Treasury page with images of all current banknotes]
* [http://www.frbsf.org/currency/ American Currency Exhibit at the San Francisco Federal Reserve Bank]
* [http://www.measuringworth.com/uscompare/ Relative values of the US dollar, from 1790 to 2006]
* [http://www.uspapermoney.info/ Summary of BEP Production Statistics]
* [http://www.wheresgeorge.com/ U.S. Currency tracking experiment]
* [http://www.currencytrading.net/2007/50-factors-that-affect-the-value-of-the-us-dollar/ 50 Factors that Affect the Value of the US Dollar – Currency Trading.net]
* [http://arxiv.org/abs/1207.4069 Askar Akaev forecasts the collapse of US dollar in December 2012]

===Images of U.S. currency and coins===
* [http://www.newmoney.gov/currency/images.htm U.S. Bureau of Engraving: Banknotes]
* [http://www.usmint.gov/about_the_mint/CoinLibrary/index.cfm U.S. Mint:  Image Library]
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