 In the 1950s the United States experienced what is known as the Second Red Scare which lasted roughly from the late 1940s to the late 1950s, during the height of the Cold War between the United States and the Soviet Union.During this period, Wisconsin Senator Joseph McCarthy led anti—communist investigations which included making accusations of disloyalty, subversion, or treason; thousands of citizens were accused of being Communists or Communist sympathizers and became the subject of unlawful investigations and questioning before government or private-industry panels, committees and agencies.Most of these accusations were unfounded and had very little evidence to support them.