United States Air Force
The United States Air Force (USAF) is the aerial and space warfare service branch of the United States Armed Forces. It is one of the five branches of the United States Armed Forces, and one of the seven American uniformed services. Initially formed as a part of the United States Army on 1 August 1907, the USAF was established as a separate branch of the U.S. Armed Forces on 18 September 1947 with the passing of the National Security Act of 1947. It is the youngest branch of the U.S. Armed Forces, and the fourth in order of precedence. The USAF is the largest and most technologically advanced air force in the world. The Air Force articulates its core missions as air and space superiority, global integrated intelligence, surveillance, and reconnaissance, rapid global mobility, global strike, and command and control.
United States Army Air Forces
The United States Army Air Forces (USAAF or AAF), informally known as the Air Force, was the aerial warfare service of the United States during and immediately after World War II (1939/41–1945), successor to the previous United States Army Air Corps and the direct predecessor of the United States Air Force of today, one of the five uniformed military services. The AAF was a component of the United States Army, which in 1942 was divided functionally by executive order into three autonomous forces: the Army Ground Forces, the Services of Supply (which in 1943 became the Army Service Forces), and the Army Air Forces. Each of these forces had a commanding general who reported directly to the Army Chief of Staff.