Originally taken August 16, 1956 and was re-issued in 1960 after Kennedy won the Democratic nomination for president in 1960.
To be certain the photo is in the public domain, original registrations in the artwork category were checked for the original year of the photo, 1956 and in 1960, when UPI re-issued this photo. No registrations for UPI or United Press International were found for either year. There's no evidence that copyright was ever filed for this photo.
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 (50 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=Photo of Senator John F. Kennedy placing the name of Adlai Stevenson into nomination as the Democratic presidential candidate for 1956 in Chicago. |Source=[http://www.ebay.com/itm/Set-of-12-vintage-press-photos-of-President-J...