In October 1947 the House Committee on Un-American Activities summoned screenwriters and directors to answer for communism in the film industry. Ten — among them Dalton Trumbo, John Howard Lawson, Ring Lardner Jr., and Albert Maltz — refused on First Amendment grounds to answer whether they were or had ever been Communists, arguing that Congress had no power to inquire into belief. All ten were cited for contempt of Congress, convicted, and, when the Supreme Court declined review in 1950, served sentences of six months to a year.
Trumbo and Lawson entered the same federal prison at Ashland, Kentucky where, in a celebrated irony, Trumbo encountered J. Parnell Thomas, the HUAC chairman who had presided over the hearings, himself imprisoned for payroll fraud. The studios' Waldorf Statement blacklisted the Ten the week of the contempt citations, inaugurating an industry purge that lasted more than a decade and rested on hundreds of careers; Trumbo, writing under fronts, won two Academy Awards he could not claim. The Ten established the template of the era: prison not for acts, but for refusing to name beliefs and associates.