When was the United States Air Force established as a separate branch of the military?

The establishment of the United States Air Force as a separate branch of the military occurred on September 18, 1947. This date marks a significant transformation in U.S. military organization, resulting from the National Security Act of 1947, which created the Air Force as an independent service, separate from the Army and Navy. This change was driven by the recognition of air power’s critical role in modern warfare, particularly in the aftermath of World War II, where air superiority proved essential to military success.

Other dates mentioned in the choices hold various historical significance but do not pertain specifically to the establishment of the Air Force. For example, July 4, 1776, is recognized as Independence Day in the United States, marking the adoption of the Declaration of Independence. December 7, 1941, is remembered for the attack on Pearl Harbor, which led to the United States' entry into World War II. November 11, 1918, signifies the end of World War I, known as Armistice Day. Each of these dates is tied to crucial moments in U.S. history, but September 18, 1947, specifically marks the birth of the Air Force as an autonomous military branch.