Joseph M. McCarthy was a U.S. Senator from Wisconsin, serving from 1947 until his death in 1957. He is best known for his role in the anti-communist movement during the early Cold War, particularly for his aggressive investigations into alleged communist infiltration in the U.S. government and other institutions. This period, known as McCarthyism, was marked by heightened political repression and a culture of fear regarding communism. McCarthy's tactics included public accusations and hearings, which often lacked substantial evidence. His approach led to significant controversy and criticism, ultimately resulting in a decline in his influence after a televised hearing in 1954. He was later censured by the Senate for his conduct, and his legacy remains a complex topic in American history.