The Federal Bureau of Investigation and the House Committee on Un-American Activities (later called the House Un-American Activities Committee, or HUAC) developed a working relationship in the period 1938 through 1975 that increased the authority of the committee and gave the bureau power to investigate suspected communists. The archive is divided into three parts. The first part, 1938-1945, documents clashes between HUAC chairman Martin Dies and the administrations of Franklin D. Roosevelt and Harry Truman. The second section, 1946-1949, records the process by which the FBI and HUAC chose their targets. The final section follows HUAC, renamed the Internal Security Committee, in its attempt to protect the FBI from other congressional investigative committees.