Joseph McCarthy is the most unjustly demonized individual in American history. In February 1950, McCarthy, a Republican senator from Wisconsin, launched a massive campaign against alleged Communists and Soviet agents working for, and perhaps spying on, the U.S. government. In Senate hearings stretching across much of the first half of the 1950s, he accused numerous U.S. government employees, including many in the State Department, of being Communists or even agents of Soviet Intelligence. He was bitterly opposed by powerful members of the Senate, by numerous high-ranking officials within both the Truman and Eisenhower administrations, and by the overwhelming preponderance of...