In 1947, the House Committee on Un-American Activities (HUAC), chaired by J. Parnell Thomas, held a series of hearings on alleged communist infiltration into the Hollywood motion picture industry. Twenty-four "friendly" witnesses—including Gary Cooper, Ronald Reagan, and Walt Disney—testified that Hollywood was infiltrated with communists, and identified a number of supposed subversives by name. Ten "unfriendly" witnesses—including Dalton Trumbo, Lester Cole, and Ring Lardner, Jr.—refused to cooperate with the Committee, contending that the investigations themselves were unconstitutional. The "Hollywood Ten," as they came to be known, were convicted of contempt of Congress and eventually served sentences of six months to one year in jail.

Shortly after the hearings, more than 50 studio executives met secretly at the Waldorf-Astoria Hotel in New York. They emerged with the now infamous "Waldorf Statement," with which they agreed to suspend the Hollywood Ten without pay, deny employment to anyone who...