Multiple choice McCarthyism in the 1950s is most closely associated with claims that communists had infiltrated the federal gov't efforts to prevent pro-communist gov'ts in Latin America formation of the Warsaw Pact passage of the Interstate Highway Act Reveal answer Fill a bubble to check yourself A Correct answer Explanation McCarthyism refers to the intense anti-communist suspicion in the United States during the early 1950s, characterized by Senator Joseph McCarthy's unsubstantiated claims that communists had infiltrated the U.S. government.