Tuesday marks the United States Air Force's 71st birthday.
On Sept. 18, 1947, the Air Force was separated into an independent branch of the military when Stuart Symington was sworn in as the first secretary of the Air Force.
Between 1909 (when the U.S. military purchased its first aircraft) and 1947, the service now called the Air Force 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), and United States Army Air Forces (1941).
There are over 50 Air Force bases and 10 joint bases in the United States, plus numerous Air Force stations. Colorado Springs boasts four of these installations (Peterson Air Force Base, Shriever Air Force Base, the United State Air Force Academy and Cheyenne Mountain Air Force Station.
Here are some tweets in celebration of the Air Force's birthday: