United States Departmet of the Air Force

The United States Department of the Air Force (DAF) is one of the three military departments within the Department of Defense of the United States of America. The Department of the Air Force was formed on September 18, 1947, per the National Security Act of 1947 and it includes all elements and units of the United States Air Force (USAF) and the United States Space Force (USSF).

Source: United States Department of the Air Force on Wikipedia.