In February 1950, Senator Joseph McCarthy rose suddenly to national fame when he claimed "I have here in my hand a list" of over 200 communists who were employed in the State Department.[94] In September 1950, the US Congress passed the McCarran Internal Security Act, which required communist organizations to register with the government, and formed the Subversive Activities Control Board to investigate persons suspected of engaging in subversive activities. High-profile hearings involving alleged communists included the 1950 conviction of Alger Hiss, the 1951 trial of the Rosenbergs, and the 1954 investigation of J. Robert Oppenheimer.[2]