Truman directed security agencies to screen employees for signs of disloyalty.
Throughout his presidency, Truman had to face allegations that the federal government was harboring Soviet spies of the highest level. The testimony of Congress on this issue attracted national attention, and thousands of people were fired for safety.
In August 1948, Whittaker Chambers, a former Soviet spy and former editor of Time magazine, confessed to the Anti-American Activities Committee and presented a list of possible members of a secret network of communists who worked in the United States government during the 1930s. One of them was Alger Hiss, a senior official of the State Department, but Hiss denied the accusations.
The Committee's statements led to a crisis in American political culture, with Hiss being convicted of perjury in a controversial trial. On February 9, 1950, Republican Senator Joseph McCarthy accused the Department of State of having Communists in its services, and specifically it was also said that the Secretary of State, Dean Acheson, knew it and that he was protecting 205 Communists in the Department.
In pointing out this problem and attacking the Truman administration, McCarthy quickly established himself as a national figure, and his explosive allegations dominated the headlines.
