The Red Scare
The term "Red Scare" refers to a widespread fear of the potential rise of Communism.
Loyalty review Boards & Loyalty Review Program
President Truman created Loyalty Review Boards to conduct investigations of government employees suspected of Communist ties. Anyonefound to be disloyal would be fired.
McCarthyism
Joseph McCarthy was a US Senator from Wisconsin. In 1950, he claimed to have a list of Communist spies who had infiltrated the US State Department. He broadcast these claims over the radio, television, and in newspapers. Eventually, when asked to produce evidence of his claims, people realized he was lying.
"McCarthyism" refers to tge height of anti - Communist hysteria in the 1950s and to the practice of making fase claims against innocent people.