The California Labor School was cited as a "subversive and Communist organization in San Francisco, California," by President Harry S. Truman's Attorney General Tom Clark in lists furnished the Loyalty Review Board and released to the press by the United States Civil Service Commission June 1 and September 21, 1948.
Sponsoring organizations of the California Labor School included numerous CIO locals, the American Veterans' Committee of California, CIO councils, the Communist Party and its various fronts, and local leaders of the National Lawyers Guild, and the Joint Anti-Fascist Refugee Committee.[1]
Instructor of atomic energy at the California Labor School is Dr. Frank Oppenheimer, brother of Dr. J. Robert Oppenheimer, director of the Los Alamos Manhattan project.
In California Labor School in San Francisco v. S.A.C.B. (CA DC.) 1957, after hearings, the Subversive Activities Control Board affirmed the hearing examiner's recommended finding requiring California Labor School to register as Communist front. In 1957 the School ceased operation.[2]