Testimony of John Thomas Watkins before the House Un-American Activities Committee, House Report No. 1579, 83rd Congress, 2nd Session, 1954
Called before a subcommittee of the House Un-American Activities Committee, John Thomas Watkins, an Illinois labor union organizer, readily answered questions about himself and others he knew to be active in the Communist Party, but he refused to speak about former associates not engaged in communist activities. He was convicted of contempt of Congress.
Records of the U.S. House of Representatives, National Archives and Records Administration
Constitutional Rights v. Congressional Powers
From the 1930s through the 1950s, Congress intensively investigated perceived political radicals. The House Committee on Un-American Activities focused on suspected communists in the film industry, universities, and labor organizations. Some witnesses refused to testify, pleading the Fifth Amendment—the right not to incriminate oneself. In 1954 labor organizer John Thomas Watkins directly challenged a subcommittee’s right to demand information not pertinent to the investigation. Watkins was convicted of contempt of Congress, but in 1957 the United States Supreme Court decided in his favor, limiting Congress’s investigative powers.
The Bill of Rights is applicable to congressional investigations, as it is to all forms of governmental action
Chief Justice Earl Warren, Watkins v. United States, 1957