 Domestically , the Cold War was in the forefront of national consciousness . 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 . 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 . 
