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 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
This image is in the public domain because according to the Copyright Law of Ghana ("Copyright Act, 2005, Act 690", р. 5/2005), "Work is not copyrighted if the work is:
Law, sub-law act or other kind of law act.
Official materials of state authorities or materials published by any other person or institution which do public function.
Official translations of materials of state authorities or translation of materials published by any other person or institution which do public function.
Any of acts in judgment processes."
Hence it is assumed that this image has been released into public domain.