; Whereas the standard for courage, flexibility, and intrepidity in combat was established for all Airmen during the first aerial raid in the Pacific Theater on April 18, 1942, when Lieutenant Colonel James Jimmy H. Doolittle led 16 North American B–25 Mitchell bombers in a joint operation from the deck of the USS Hornet to strike the Japanese mainland in response to the Japanese attack on Pearl Harbor; Whereas the National Security Act of 1947 ( 50 U.S.C. 3001 et seq.), signed into law by President Harry S. Truman, realigned and reorganized the Armed Forces to establish the Department of the Air Force (referred to in this preamble as the USAF ) as separate from other military services; Whereas, on September 18, 1947, W. Stuart Symington became the first Secretary of the newly formed and independent USAF, marking the date on which the USAF was established; Whereas, on September 26, 1947, General Carl A. Spaatz, a pioneering aviator and former Commanding General of the Army Air Forces, became the first Chief of Staff of the USAF; Whereas the Air National Guard was also created by the National Security Act of 1947 and has played a vital role in guarding the United States and defending freedom in nearly every major conflict and contingency since its creation; Whereas, on October 14, 1947, the USAF demonstrated the historic and ongoing commitment of the USAF to technological innovation when Captain Charles Chuck Yeager piloted the X–1 developmental rocket plane to a speed of Mach 1.07, becoming the first flyer to break the sound barrier in a powered aircraft in level flight; Whereas the Air Force Reserve, created on April 14, 1948, is comprised of citizen airmen who serve as unrivaled wingmen of the active duty USAF during every deployment and on every mission and battlefield around the world in which the USAF is engaged