Powered flight was pioneered in the United States in 1903 but meetings between the US military and the Wright Brothers did not take place until 1907. It was another four years before the United States Army provided the funds to purchase aircraft. In 1913 the US Army Air Service opened a training school at San Diego. The same year saw the US Navy establish its own flying school at Pensacola.

A squadron of US Army Air Service took part in the 1917 expedition into Mexico, but all crashed or were lost in action. This reinforced the belief that more money was needed for better equipment and training.

By 1917 the US Army Air Service possessed 1,185 serving personnel and 260 planes. However, none of these aircraft were fit for combat duties. Congress voted $640 million to build 22,000 planes based on the latest French designs. Over 5,000 planes based on the British-designed Airco DH-4 were also produced. The most successful USA designed aircraft was the Curtiss H-16. However, it was not until 1918 that US produced aircraft began arriving on the Western Front.

Major William Mitchell was given responsibility for the training and organisation of the pilots in France. The first US fighter patrols over German lines began in March 1918 and played an important role during action at St Mihiel and Meuse-Argonne. The leading USA Flying Aces included Edward Rickenbacker (26), Frederick Gillet (20) and Wilfred Beaver (19).