The official date of the founding of the US Air Force is September 18th, 1947 under the National Security Act.¬†It is the most recent branch of the U.S. military to be formed, and is the largest and one of the world’s most technologically advanced air forces. It was a momentous event that over six decades later has demonstrated the achievement of an Air Force second-to-none, yet the Air Force’s history and heritage goes back a lot further.
From the time that the US military purchased its first aircraft in 1909 up to 1947, the US Air Force did not exist as a separate and independent military service organization. It went through a series of designations: Aeronautical Section, Signal Corps (1909); Aviation Section, Signal Corps (1914); United States Army Air Service (1918); United States Army Air Corps (1926), United States Army Air Forces (1941).
WWII illustrated the value of airpower, and the need to change the basic organization of the US Military Forces.  The result was the creation of a single Department of Defense with a strong Joint Chiefs of Staff with Army, Navy, and Air Force chiefs.  In 1947 President Truman signed the National Security Act which established this new defense organization, and along with it the creation of the US Air Force as an independent service, equal to the US Army and US Navy.  The official birthday of the US Air Force is 18 September 1947.
Through the years history has shown the wisdom and foresight of the creation of a separate Air Force.  The US Air Force emerged quickly from its cradle and began to create its own history and heritage.
1949:  The flight of the “Lucky Lady II” demonstrated  the Air Force’s capability to fly, non-stop round the world, showing it could take off from the U.S. and drop bombs anywhere in the world.
1950-1953:  USAF engaged in the first completely jet aerial combat During the Korean War.  The F-86 Saberjet scored impressive aerial victories against the enemy MiG-15.
1954:  The first B-52 Stratofortress came into the USAF Inventory and has served in every conflict since its appearance.
1960s: The development and deployment of Intercontinental Ballistic Missiles (ICBMs) as a major component of the aerial defense capability of the United States.
1964-1973:  War in Vietnam
1970s:  The development of laser-guided bombs and TV-guided air to ground missiles. Air mobility took a major step forward with the introduction of the C-5 Galaxy in the Air Force Inventory.  Other aircraft systems  introduced in this decade were the F-15, A-10, AWACS, and F-16.
1980s:  Stealth Technology was revealed advent of the F-117; strategic bomber capability was increased with the deployment of the B-1.
1990s:  USAF played a major role in the swift defeat of the Iraqi military forces in the first Persian Gulf War:  The Air Force underwent a major reorganization with the formation of Air Combat Command, Air Mobility Command, and Air Force Materiel Command.  The USAF supported the war in the Balkans, and the US intervention  Operation Uphold Democracy in Haiti.
2000 — Present: The Expeditionary Air Force concept was a major transition in how the Air Force employed forces.¬†¬† The Global War on Terrorism brought the USAF into Operation ENDURING FREEDOM and Operation IRAQI FREEDOM.
(Original article from http://www.military.com/air-force-birthday)
