Gary Cooper takes the stand at the House Un-American Activities Committee, 1947 Credit: APA In October 1947, the ‘Hollywood Ten’ were summoned before the House Un-American Activities Committee in Washington DC – part of an investigation into the influence of communism in the movie business. Ahead of the hearings, 41 filmmakers had been subpoenaed; the Hollywood Ten were among the “unfriendly witnesses” who refused to answer the big question – “Are you now or have you ever been a member of the Communist Party?” – or snitch on friends and colleagues. Well-meaning liberals from the Hollywood elite – including Humphrey Bogart, Lauren Bacall, Danny Kaye, Judy Garland, Edward G. Robinson, Groucho Marx, and Frank Sinatra – banded together to form the Committee for the First Amendment, to protest what they saw as an affront to free speech and thought. Members of the group, led by Bogart and Bacall, flew to DC to attend the hearings.