The first use of aircraft as a method for dropping bombs on an enemy was the largely unsuccessful use of aircraft by Germany in World War I. The appearance of these behemoths over Britain was intimidating, but the giant airships were highly susceptible to attack by nimble fighter planes, and although they did do some damage they had little effect on the outcome of the war.

Following World War I, it was already obvious that airplanes, well-established as fighting machines, couldalso be use to transport bombs. All that was needed was sturdier planes with more powerful engines. Bombs are deliberately designed to be heavy, to give them greater ability to punch through defensive armor possessed by and enemy, and planes would need to have respectable payload capacity to be effective as bombers.

Spurred by the tireless efforts of World War I aviation hero Billy Mitchell, the...