The Services of Supply or "SOS" branch of the Army of the USA was created on 28 February 1942 by Executive Order Number 9082 "Reorganizing the Army and the War Department" and War Department Circular No. 59, dated 2 March 1942. Services of Supply became one of the three autonomous components of the Army of the United States on 9 March 1942. It was renamed the Army Service Forces on 12 March 1943, as it was felt that the term "supply" did not accurately describe its broad range of activities. From the day of inception in 1942 through the end of WWII, the SOS/ASF was commanded by Lieutenant General Brehon B. Somervell.

The Army Service Forces was one of the three autonomous components of the United States Army during World War II, the others being the Army Air Forces and Army Ground Forces, created on 9 March 1942. By dividing the Army into three large commands, the Chief of Staff, General George C. Marshall, drastically reduced the number of officers and agencies reporting directly to him. The Army Service Forces brought together elements of five different components of the Army: elements of the War Department General Staff (WDGS), especially its G-4 division ; the Office of the Under Secretary of War; the eight administrative bureaus; the nine corps areas, which became service commands; and the six supply arms and services, which became known as the technical services. The Army Service Forces was initially known as the United States Army Services of Supply but the name was changed on 12 March 1943, as it was felt that the term "supply" did not accurately describe the broad range of its activities. The Army Service Forces was abolished on 11 June 1946 and most of its functions were taken over by the War Department General Staff.