He studied political science at the University of California at Los Angeles but had to drop out to help support his family and completed his degree forty years later.
He also mentioned alleged communists known to him, including Harry Bridges (strike organizer), Schneiderman (California CP), J. Robert Oppenheimer (atomic scientist), and Haakon Chevalier (translator).
In 1939, the US government sought to revoke his citizenship shortly after Joseph Stalin reversed Soviet (Comintern) foreign policy by signing the Hitler-Stalin Pact.
Schneiderman was the American Committee for the Protection of Foreign Born's second major victory, following work for Harry Bridges, leader of the International Longshoremen's Association (ILA) during the 1934 West Coast waterfront strike.
[15] In 1949, Schneiderman and 14 other California party leaders found themselves indicted and then convicted under the Smith Act for trying to overthrow the government.
The defendants were: Loretta Starvus Stack, Al Richmond, Dorothy Healey, Rose Chernin Kunitz, Albert J. Lima, Philip Marshall Connelly, Ernest Otto Fox, Carl Rude Lambert, Henry Steinberg, Oleta O'Connor Yates, and Mary Bernadette Doyle.
[6] When the case closed in 1952, Schneiderman attributed it to "prejudice and hysteria" and predicted that "the time will come when our country will not look back with pride on prosecutions of this kind.
[5][6]The Labor Archives and Research Center of San Francisco State University houses Schneiderman's papers.
[2] At the Tamiment Library, Schneiderman appears in collections including those of Carol Weiss King,[14] Gil Green,[17] Samuel Adams Darcy,[18] and Max Schachtman.