Hage's Dairy Cards, published between 1949 and 1951, were not renewed with the United States Copyright Office, meaning these cards have fallen into the public domain.
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.
{{Information |Description=Major League baseball pitcher en:Russ Christopher with the minor league San Diego Padres in 1951. |Source=http://www.vintagecardprices.com/card-profile/184810/1951-Hages-Dairy-Russ-Christopher-4-Baseball-Card-Value-Price...