The House Un-American Activities Committee (HUAC) of the U.S. Congress opens its investigation into communist infiltration of the American movie industry on October 20, 1947. Chaired by Congressman Parnell Thomas, the subsequent hearings focused on identifying political subversives among Hollywood actors and actresses, writers, and directors. Although initially opposed by a group of Hollywood heavyweights such as Humphrey Bogart, Lauren Bacall, and Gene Kelly, the hearings proceeded. A number of witnesses, including studio owners Walt Disney and Jack Warner, and movie stars Robert Taylor and Gary Cooper, gave statements decrying the communist influence in the film industry; some specifically named colleagues whom they suspected of communist affiliations or sympathies. Another group of witnesses, including writers Dalton Trumbo and Ring Lardner Jr., were less forthcoming, and loudly complained that the hearings were illegal, and that questions about their political loyalties were inappropriate.
Eventually, the "Hollywood Ten," as these protesting witnesses came to be known, were found in contempt of Congress and went on to serve jail terms.The fate of the Hollywood Ten terrified many in the film industry, and when new HUAC hearings started in 1951, Hollywood quickly buckled to the committee's demands. Hundreds of performers, directors, writers, and others associated with the movies were placed on a "blacklist," effectively banned from employment. Actors such as Zero Mostel and John Garfield saw their careers in film during the 1940s and 1950s destroyed for refusing to cooperate with HUAC. Hollywood also responded by turning out a bevy of films with anticommunist themes, such as I Was a Communist for the FBI (1951), Big Jim McClain (1952), and My Son John (1952).