The photo is a cropped version of the original, which is Order Number B015753 in the National Library of Medicine. The date and author (below) are taken from the NLM's MARC record. The photograph was published in 1955 without a copyright notice. The photo has been cropped, color level adjusted (via curve), desaturated, healed to fix minor defects, and converted to JPEG (quality level 88), with the GIMP 2.6.6.
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.