English: Photo of all 5 Marx brothers from an appearance they made on the Tonight! show. From left-Harpo, Zeppo, Chico, Groucho and Gummo.
Date
This photo was originally taken and published by NBC prior to the 1961 death of Chico Marx, as all five brothers appeared as guests on the program. It was taken by an NBC press employee--appears to have been taken in one of the "green rooms" at Rockefeller Center. However, the earliest date stamp is May 18, 1970.
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.