Joseph McCarthy (1908-1957) was a United States Senator from Wisconsin whose aggressive anticommunist pursuits after 1950 made him the namesake for "McCarthyism."
In 1950, McCarthy created a national sensation by claiming to have a list of 205 names of known Communists inside the State Department. (The list was bogus.) For the next four years, he continued to make more and more spectacular attacks on alleged Communists inside the government. His downfall came when he made a series of unwarranted attacks against the United States Army, which fought back in a series of nationally televised hearings that destroyed McCarthy's credibility.