Air Force Day was established on August 1, 1947, by President Truman "in recognition of the personnel of the victorious Army Air Forces and all those who have developed and maintained our nation's air strength." August 1 was chosen to mark the 40th anniversary of the establishment, in 1907, of the Aeronautical Division in the Office of the Chief Signal Officer of the Army.
Air Force Day came into being immediately after the signing of the National Security Act of 1947, although the status of the air element of the military was uncertain. Thus, although it was called Air Force Day, its first celebration was staged by the Army Air Forces and not by the U.S. Air Force.
Underlying the Air Force Day celebration was a need to increase "both official and public awareness of the priority of importance of air forces in any system of national security," according to Mr. Truman. "The great strategic fact of our generation is that the United States now possesses live frontiers -- the frontiers of the air -- and that the oceans are no longer sure ramparts against attack."
In his message to the nation on the first Air Force Day, Mr. Truman said, "I remind all of our citizens that the air power of the nation is essential to the preservation of our liberty, and that the continued development of the science of air transportation is vital to the trade and commerce of a peaceful world."
Air Force Day was last observed on August 1, 1949.