Under the National Security Act of 1947, the U.S. Army Air Forces became the independent United States Air Force, with W. Stuart Symington sworn in as its first Secretary. The change reflected lessons from World War II, where strategic bombing and air superiority had proven decisive, and set the stage for the Air Force's central role in the nuclear-armed Cold War standoff that followed.
For decades, American airpower advocates like Billy Mitchell had argued, often at the cost of their careers, that aviation deserved to be its own military service rather than an appendage of the Army. World War II settled the argument in practice if not yet in law: strategic bombing campaigns over Germany and Japan, and the atomic strikes that ended the Pacific war, made clear that air forces could now win wars largely on their own terms.
The National Security Act of 1947, signed by President Truman aboard his aircraft the Sacred Cow in July, restructured the entire American defense establishment, creating the Department of Defense, the CIA, and the National Security Council alongside the new Air Force. On September 18, the transition became official, with Stuart Symington taking office as the first Secretary of the Air Force and General Carl Spaatz becoming its first Chief of Staff.
The timing mattered enormously. The new service was born just as the Cold War hardened, and it would soon control the nation's nuclear-armed bomber fleet through the Strategic Air Command — arguably the most consequential military asset of the entire standoff with the Soviet Union. What began as a bureaucratic reorganization quickly became the backbone of American nuclear deterrence.
Key people: W. Stuart Symington, Carl Spaatz, Harry Truman