Joseph McCarthy was known for his investigations of supposed communists in government departments during the Cold War era of the 1950s. As chairman of the Senate's Committee on Government Operations, he launched a media-fueled anti-communist crusade that became so virulent that unsubstantiated attacks on political opponents became known as McCarthyism.
Joseph McCarthy was elected to the U.S. Senate in 1946 during an era when the House Un-American Activities Committee epitomized a strong anticommunist sentiment within the American government and people. McCarthy sensationally capitalized on this mood in 1950, when during a speech he claimed to have the names of 205 communists who had infiltrated the State Department. After his re-election to the Senate in 1952, McCarthy used his chairmanship of the Committee on Government Operations to accuse many government employees of communist sympathies, although he was never able to substantiate his accusations. His high media profile and belligerent attitude made up for the lack of evidence. He wielded so much influence that even President Eisenhower was unable to challenge him openly.
In 1954, McCarthy shifted his focus toward uncovering supposed communist influence in the armed forces. The hearings he conducted were nationally televised, and he was exposed as an overbearing bully. Soon afterward, the Senate took away his committee chairmanship and voted to censure him for conduct contrary to the traditions of the Senate. He died in 1957 at the age of 48 due to complications related to alcoholism.