Which date is recognized as the Air Force's birthday?

The date recognized as the Air Force's birthday is September 18, 1947. This date marks the establishment of the United States Air Force as a separate branch of the armed forces. Before that date, airpower was part of the U.S. Army, but the need for a dedicated aerial military force was recognized, leading to the Air Force's creation under the National Security Act of 1947.

Understanding the significance of this date is crucial as it represents the transformation of airpower into an independent and essential component of national defense strategy. The other dates provided refer to different branches or events in military history, which, while significant, do not pertain to the Air Force's establishment as a distinct service.