The U.S. House of Representatives created HUAC, or the House Un-American Activities Committee, in 1938 to investigate American citizens with suspected political affiliations with Nazi Germany. After World War II, it focused primarily on citizens with communist and socialist affiliations.
HUAC grew out of a number of earlier committees including the Overman Committee (1918-1919), the Fish Committee (1930) and the McCormack-Dickstein Committee (1934-1937), all of which investigated U.S. citizens with suspected ties to Germany or the USSR. The House of Representatives made HUAC permanent in 1945. The committee quickly became known for forcing U.S. citizens to testify before Congress, both to explain their political beliefs and name others who held similar beliefs. Because HUAC hearings were held in an intimidating atmosphere, their results were often questionable, and the beliefs of the individuals under investigation were often exaggerated.
HUAC also maintained the Hollywood Blacklist, a list of writers, directors, and actors who held subversive beliefs, including Charlie Chaplin, Henry Miller and Orson Welles. Major studios boycotted artists who had been blacklisted for fear that they themselves would be blacklisted and boycotted.
To this day, HUAC is often inaccurately associated with Sen. Joseph McCarthy, who undertook similar anti-communist work around the same time. When McCarthy began investigating members of the U.S. Army, the American public began to see his and HUAC's tactics as oppressive and unnecessary, and both entities began to lose support. HUAC changed its name to the Committee on Internal Security in 1969, after which the committee lost its subpoena power and was terminated in 1975.