In 1947, President Truman had ordered background checks of every civilian in service to the government. When Alger Hiss, a high-ranking State Department official was convicted on espionage charges, fear of communists intensified.
McCarthy capitalized on national paranoia by proclaiming that Communist spies were omnipresent and that he was America's only salvation.
An atmosphere of fear of world domination by communists hung over America in the postwar years. There were fears of a nuclear holocaust based on the knowledge that the Soviet Union exploded its first A-bomb in 1949. That same year, China, the world's most populous nation, became communist. Half of Europe was under Joseph Stalin's influence, and every time Americans read their newspapers there seemed to be a new atomic threat.
At a speech in Wheeling, West Virginia, on February 9, 1950, McCarthy launched his first salvo. He proclaimed that he was aware of 205 card-carrying members of the Communist Party who worked for the United States Department of State. A few days later, he repeated the charges at a speech in Salt Lake City. McCarthy soon began to attract headlines, and the Senate asked him to make his case.

License information: CC BY 4.0
MPAA: G
Go to source: https://www.commonlit.org/texts/mccarthyism