General Henry H. Arnold, Chief of the US Army Air Forces; Air Chief Marshal Sir Arthur Harris, Commander in Chief of the Royal Air Force Bomber Command; and General Ira C. Eaker, Commander of the Eighth Air Force, strolling on the lawn of Springfields, Harris’ official residence in Buckinghamshire, September 1943. © IWM

Seventy-five years ago, on September 18, 1947, the United States Air Force (USAF) was officially established as a separate branch of the US Armed Forces, but the history of US aerial warfare goes back much further.

Though the Wright brothers made the first powered flight at Kitty Hawk, North Carolina, in 1903, the US was slow to get aerial warfare off the ground. While the US Army had established the Aeronautical Division within the US Signal Corps on August 1, 1907, as aircraft were purely seen as a platform for enemy observation, the US lacked the necessary motivation to significantly expand its airpower capacity until it declared war against Imperial Germany in April 1917.

By this time, aerial combat had progressed significantly. During World War I, Britain, France, and Germany had all developed the airplane as an instrument of war and put it to use over the trenches to direct artillery, carry out bombardment, and shoot down enemy fighters. While the US was reliant on its more experienced allies to provide training and supply most of its combat aircraft during World War I, it soon recognized the possibility of aerial warfare.

American Airmen work on a Nieuport Scout on the Western Front. The US relied on its British and French allies for training and equipment during World War I, but also learned the potential of aerial warfare from them. ©IWM

Inspired by these opportunities and following the precedent set by Britain’s establishment of the Royal Air Force in 1918, American flying units lobbied for the creation of a separate air branch of the US Armed Forces. The US Army refused, failing to see the benefits of airpower beyond its support for ground troops, but nevertheless accepted the creation of the US Army Air Service as a combatant arm in 1920.

As the US adopted an isolationist approach to foreign policy after World War I, spending on military aviation was severely reduced. Leaders in the Air Service, particularly General William “Billy” Mitchell, who had been a commander in France, nevertheless continued to argue the value of airpower as a potential war-winning strategy. Mitchell was so determined to prove that aerial bombardment was a vital tool for national defense, he overstepped his office and was court-martialed in 1925. But this paid off when the Army Air Service was eventually raised in status to the Army Air Corps in 1926, authorizing a program of expansion.

The debut of the Boeing 299 (later designated the B-17 Flying Fortress) in July 1935. The aircraft would shape the US Army Air Corps strategy into World War II. ©IWM

While American military aviation had only made incremental gains since the end of World War I, civil air transport had progressed massively. By the 1930s, American manufacturers could build sophisticated aircraft that could travel at high speeds over great distances. At one of the US Army’s regular competitive trials for experimental aircraft in 1934, Boeing debuted the world’s first all-metal four-engine bomber. Though the isolationist elements of the US establishment saw little use for the aircraft at that time, the Air Corps ordered 13 of them, confident that it would prove their theories.

The Air Corps equipped their new aircraft, designated B-17 and later dubbed “the Flying Fortress,” with the Norden bombsight. Together this equipment produced such outstanding accuracy on practice aerial bombing runs, the Air Corps asserted they could drop a bomb into a pickle barrel from five miles up. This fostered the doctrine of daylight high-altitude precision bombing, favored by leaders of what became the United States Army Air Forces (USAAF) in 1941, in the years to come.

A B-17 Flying Fortress bombs a German aircraft factory in 1943. The USAAF hoped daylight precision bombing would prove a winning strategy during World War II, which would justify the independence of US airpower if it succeeded. US official photo

World War II eventually presented USAAF commanders with the opportunity to assert their belief in the supremacy of airpower. With Britain as the staging ground for the war in Europe, the way was open to pursue a program of aerial bombardment of specific industrial, economic, and military targets that were seen as vital to Nazi Germany’s war effort. Leaders knew that if their system of bombing worked, airpower would become the dominant military force, and they could justify full autonomy for US aerial warfare.

The Eighth Air Force, which began arriving in Britain in 1942, became the instrument for this experiment. Weather and German air defenses, however, quickly proved that daylight precision bombing would be unable to bring Nazi Germany to its knees in the way USAAF leaders hoped. Hindered further by unsuitable equipment and an underestimation of the Nazi war machine’s ability to recover, the USAAF’s bombing campaign had little profound effect until the summer of 1944, when the ground invasion of Europe was well underway.

The atomic bombing of Hiroshima and Nagasaki (pictured) in August 1945 led to Imperial Japan’s unconditional surrender and demonstrated the importance of US airpower. ©IWM

USAAF leaders, however, never gave up on their belief that the bomber could deliver victory. The B-29 Superfortress, introduced in 1944 and capable of attacking Imperial Japan from the safety of US bases in the Pacific or China, was deployed on long-range fire-bombing missions against Japanese cities starting in spring 1945. Despite the devastating and indiscriminate damaged caused on these missions, Japan refused to surrender until the USAAF dropped atomic bombs over Hiroshima and Nagasaki in August 1945.

While in practice the USAAF had acted independently during World War II, its leaders continued to press for full autonomy as a separate military force. Even after demobilization and re-organization in 1945, it was clear that nuclear weapons had made airpower the preeminent force in the postwar world, and so the US Air Force was finally established under the National Security Act on September 18, 1947.

In the 75 years since its establishment, the USAF has played a significant role in many major conflicts and continues to fulfil its mission to deliver airpower in defense of the US today.

The American Air Museum in Britain spotlights the heroics of generations of airmen and women who have proudly worn a USAF uniform throughout the decades.

We salute all members of the USAF, past and present, on their 75 years of distinguished service to the US. We are grateful for the freedoms they protect for us and delighted to give them the recognition they so richly deserve.

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