Distribution of the card itself put the full color photo in the public domain. Also published with no notice in an advertisement in The York Dispatch in 1976.
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.
Uploaded a work by A & D Productions from [https://web.archive.org/web/20210627003335/https://www.rareamericana.com/pages/books/3728429/young-senators/young-senators-promo-photo-for-washington-d-c-funk-and-r-b-band Young Senators [Promo Photo for Washington D.C. Funk and R&B Band].] with UploadWizard