When is the Air Force Birthday celebrated?

The Air Force Birthday is celebrated on September 18th, 1947, as this date marks the establishment of the United States Air Force as a separate branch of the armed services under the National Security Act of 1947. This significant event represented a pivotal moment in military history, as it allowed the Air Force to emerge from the Army Air Forces and gain its own command structure, which is essential for organizing, training, and equipping aerial forces.

The other options pertain to different historical events. June 14th, 1775, is recognized as the birthday of the United States Army, reflecting its formation as a unified force during the American Revolutionary War. November 11th, 1918, is significant for marking the end of World War I, with an armistice agreement. December 7th, 1941, is remembered for the surprise attack on Pearl Harbor, which led the United States to enter World War II. While all these dates are important in American military history, they do not relate to the founding of the Air Force.