Final answer:
Joseph McCarthy claimed to have a list of Communists in the State Department but never provided concrete evidence for his claims, despite varying the number of alleged Communists and creating widespread fear through unsupported accusations.
Step-by-step explanation:
Senator Joseph McCarthy claimed to have evidence of Communists in the U.S. State Department during the early 1950s, a period now referred to as McCarthyism. Initially, he waved a piece of paper during a speech, asserting he had a list of 205 members of the Communist Party working within the State Department. However, he never produced any concrete evidence to support these claims. As the senator was pressed for names, the number varied from 205 to 57, and then 81, showing inconsistency and a lack of substantiation. His tactics resulted in widespread fear and political turmoil but were ultimately based on unsupported accusations and unsubstantiated allegations.