The Cold War was one of the most important events of the 20th century for many reasons. Not only did it involve major wars such as the wars in Korea and Vietnam, but it also saw the United States undergo a fear of communism in its own country and a dramatic challenge to its democracy. This event is known as the period of McCarthyism or the Second Red Scare.
McCarthyism (or the Second Red Scare) was a period in the 1950's when a fear of the spread of communism in the United States. During this time thousands of American citizens were accused of and investigated for possible connections to communism. Since the United States was locked in an ideological conflict with the Soviet Union, many Americans associated communism with the enemy and sought to remove any communist elements in their own country. A fear of communism had been growing in the Unites States in the years and decades before the 1950's due to a series of significant events, including: Russian Revolution, Julius and Ethel Rosenberg, and the advancement of the Soviet nuclear program.
McCarthyism gained its name from United States Senator Joseph McCarthy who is credited with leading the anti-communist movement in the United States in the 1950's. McCarthy was a senator for Wisconsin from 1947 until his death in 1957. During his time as a senator he famously declared that the United States government was filled with communists and communist sympathizers. In particular, he claimed he had a list of communists working for the federal government and oversaw a series of investigations and hearings. McCarthy's accusations created a high level of paranoia within the United States and caused different aspects of American society to begin questioning the loyalty of American citizens.
The two most famous examples of the impact of McCarthyism on American society were the House Un-American Activities Committee (HUAC) and the Hollywood Blacklist. The HUAC was a committee of the United States House of Representatives that conducted investigations against American citizens accused of carrying out anti-American actions. In particular, the HUAC carried out a number hearings against people accused of having communist connections. The HUAC eventually was terminated after the fall from grace of Joseph McCarthy. The Hollywood Blacklist refers to a time in thee 1950's when many who worked in the entertainment industry were blacklisted as being either communist or communist sympathizers. Being blacklisted meant these people were unable to find work in the industry and several were forced to face hearings in front of the HUAC.
In the end, McCarthyism declined by the mid to late 1950's and Joseph McCarthy was widely discredited based on his claims of widespread communist involvement in the United States federal government. McCarthyism created a large debate in the United States and became a very controversial issue that still resonates today. For example, it put a great deal of pressure on American democracy by bringing into question issues of free speech and free association.