In 1947, President Truman had tried to assure Americans, "I am not worried about the Communist Party taking over the Government of the United States, but I am against a person, whose loyalty is not to the Government of the United States, holding a government job. They are entirely different things. I am not worried about this country ever going Communist. We have too much sense for that." Nonetheless, shortly after World War II, Congress' House Committee on Un-American Activities began investigating Americans across the country for suspected ties to Communism.
The most famous victims of these witch hunts were Hollywood actors, such as Charlie Chaplin, whose "Un-American activity" was being neutral at the beginning of World War II, but at the beginning of the Cold War, America was gripped by the Red Scare. The Red Scare would reach a fever pitch after Wisconsin Senator Joseph McCarthy made waves in 1950 by telling the Republican Women's Club in Wheeling, West Virginia that he had a list of dozens of known Communists working in the State Department. The political theater helped Senator McCarthy become the prominent anti-Communist crusader in the government, and McCarthy continued to claim he held evidence suggesting Communist infiltration throughout the government, but anytime he was pressed to produce his evidence, McCarthy would not name names. Instead, he'd accuse those who questioned his evidence of being Communists themselves.
The case of Alger Hiss and the rise of McCarthyism were undoubtedly instrumental in the way that one of the most notorious cases in American history unfolded in the early 1950s. After years of keeping tabs on Julius and Ethel Rosenberg, the two Communist sympathizers were indicted on charges of treason and conspiracy to commit espionage for passing off secrets about the atomic bomb to the Soviet Union