Joseph Carroll (DIA)
When the U.S. Air Force was established as a separate executive department under the National Security Act of 1947, Secretary of the Air Force W. Stuart Symington, requested FBI Director J. Edgar Hoover to loan General Carroll to the services to organize a U.S. Air Force agency for investigative and counterintelligence functions. He organized and directed this new organization, the AFOSI, along the lines of the FBI rather than the U.S. Army's Criminal Investigation Command (USACIDC or CID). General Carroll was tendered a commission as a colonel, U.S. Air Force Reserve, January 12, 1948. He was ordered to active duty in the grade of brigadier general May 6, 1948, and promoted to major general August 11, 1950.
United States Army Air Forces
Congress, at the recommendation of Truman, created the Department of the Air Force with enactment of the National Security Act of 1947 (61 "Stat". 495), 26 July 1947. The act established the United States Air Force, a completely separate branch of the U.S. military, and abolished both the Army Air Forces and the Air Corps, effective 18 September 1947. The transfer of personnel and assets from the AAF to the USAF was effected by Transfer Order 1, Office of the Secretary of Defense, 26 September 1947.