3.5" with cardboard back and bar pin. Possibly issued by students at City College of New York or by the New York Teachers Union. The object of the protest was to repeal the Feinberg Law. The button is from 'Red Scare' era which saw the conviction of Alger Hiss, the execution of the Rosenbergs, and the efforts of Sen. Joseph McCarthy to discover Communists in the U.S. government (see next item). The NY statute banned from teaching anyone who called for overthrow of the government, specifically aimed at Communists. The Supreme Court upheld the law March 3, 1952. Justices Douglas, Black and Frankfurter dissented with Frankfurter arguing the statute "Turns The School System Into A Spying Project." Celluloid has some lighter yellow marks on right side, some slight dustiness around the outer edges and a minimal bit of surface wear in reflected light. Also see buttons relating to New York Colleges issued as part of the pre-WWII peace movement #805-812. Only example we've seen in this large size.