From 1948 until his retirement in 1973, South Dakota senator Karl Mundt was known as a fierce opponent of communism. As a member—and eventually ranking member—of the Committee on Government Operations and its Permanent Subcommittee on Investigations, Mundt worked to expose communists in the government. In 1954 he chaired the Subcommittee on Investigations for the Army-McCarthy hearings, remaining loyal to Senator Joseph McCarthy. Mundt gained prominence with two major investigations into bribery allegations against officials at the Agriculture Department and the Pentagon. Mundt voted for cloture to end debate on the Civil Rights Act of 1964 after striking a deal with Republican Leader Everett Dirksen. Mundt also became one of the leading conservationists in the Senate, which earned him an award from The World Wildlife Fund in 1969. After he suffered a debilitating stroke in 1969, Senate leaders took the unprecedented step of removing Mundt from his committee assignments.