United States Air Force
The U.S. War Department created the first antecedent of the U.S. Air Force, as a part of the U.S. Army, on 1 August 1907, which through a succession of changes of organization, titles, and missions advanced toward eventual independence 40 years later. In World War II, almost 68,000 U.S. airmen died helping to win the war, with only the infantry suffering more casualties. In practice, the U.S. Army Air Forces (USAAF) was virtually independent of the Army during World War II, and in virtually all ways functioned as an independent service branch, but airmen still pressed for formal independence. The National Security Act of 1947 was signed on 26 July 1947 by President Harry S Truman, which established the Department of the Air Force, but it was not until 18 September 1947, when the first secretary of the Air Force, W. Stuart Symington, was sworn into office that the Air Force was officially formed as an independent service branch.
History of the United States Air Force
In practice, the Army Air Forces became virtually independent of the Army during World War II, but its leaders wanted formal independence. In November 1945, General Dwight D. Eisenhower became Army Chief of Staff, while General Carl Spaatz began to assume the duties of Commanding General, Army Air Forces, in anticipation of General Arnold's announced retirement. One of General Eisenhower's first actions was to appoint a board of officers, headed by Lieutenant General William H. Simpson, to prepare a definitive plan for the reorganization of the Army and the Air Force that could be effected without enabling legislation and would provide for the separation of the Air Force from the Army. On 29 January 1946 "Generals Eisenhower and Spaatz agreed on an Air Force organization composed of Strategic Air Command, Air Defense Command, Tactical Air Command, Air Transport Command, Air Technical Service Command, Air Training Command, the Air University, and the Air Force Center."