McCarthyism is the politically motivated practice of making accusations of disloyalty, subversion, or treason without proper regard for evidence. The term specifically describes activities associated with the period in the United States known as the Second Red Scare, lasting roughly from the late 1940s to the late 1950s and characterized by heightened fears of communist influence on American institutions and espionage by Soviet agents. Originally coined to criticize the anti-communist pursuits of U.S. Senator Joseph McCarthy, "McCarthyism" soon took on a broader meaning, describing the excesses of similar efforts. The term is also now used more generally to describe reckless, unsubstantiated accusations, as well as demagogic attacks on the character or patriotism of political adversaries.
During the postâ€“World War II era of McCarthyism, many thousands of Americans were accused of being Communists or communist sympathizers and became the subject of aggressive investigations and questioning before government or private-industry panels, committees and agencies. The primary targets of such suspicions were government employees, those in the entertainment industry, educators and union activists. Suspicions were often given credence despite inconclusive or questionable evidence, and the level of threat posed by a person's real or supposed leftist associations or beliefs was often greatly exaggerated. Many people suffered loss of employment, destruction of their careers, and even imprisonment. Most of these punishments came about through trial verdicts later overturned, laws that would be declared unconstitutional, dismissals for reasons later declared illegal or actionable, or extra-legal procedures that would come into general disrepute.
The most famous examples of McCarthyism include the speeches, investigations, and hearings of Senator McCarthy himself; the Hollywood blacklist, associated with hearings conducted by the House Committee on Un-American Activities; and the various anti-communist activities of the Federal Bureau of Investigation (FBI) under Director J. Edgar Hoover. McCarthyism was a widespread social and cultural phenomenon that affected all levels of society and was the source of a great deal of debate and conflict in the United States.