This United States postage stamp was published prior to 1978 and is therefore in the public domain in the United States. See Commons:Hirtle chart for further explanation. Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.
{{Information |Description={{en|US stamp honoring the Cadillac exploration}} |Source=Transferred from [http://en.wikipedia.org en.wikipedia]; transfer was stated to be made by User:Stefan4.<br/> (Original text : ''USPS'') |Date=1951<br/> ({{Date|2009|