This study examines the development of us pursuit aviation during the interwar period, 1919 to 1941. During this period, airmen struggled to develop a coherent airpower theory from their experiences in world war i. With only one war to base their theories upon, airmen based much of their developing theories upon speculation. In some ways their theories proved correct, in others, they missed the target. World war ii tested their theories and quickly highlighted the shortcomings of interwar us airpower doctrine. Pursuit aviation was one branch of us airpower where airmen had missed the mark. Us pursuit aviation entered world war ii unready to compete with the other major powers. Its equipment was substandard, its pilots were not trained in the missions they would execute, and, most importantly, pursuit aviation lacked a coherent theory on gaining air superiority. Why pursuit aviation fell short is a good question given that at the end of world war i, airmen considered pursuit the fundamental arm of the air force. Pursuit's downfall was intertwined with the rise of the bomber. When airmen realized the awesome potential of strategic bombing, their focus, and the focus of the air corps shifted from pursuit to bombardment. No longer was pursuit the fundamental arm of the air force, instead airmen recognized pursuit as a necessary supplement to bombardment. In the early 1930s, advances in bomber technology enabled bombers to out-range and out-pace concurrent fighters. This further degraded the role of pursuit, as airmen deemed pursuit no longer necessary for bombardment's success. Instead, the air corps relegated pursuit only to a defensive role against enemy bombardment. Pursuit maintained that role until the build-up for world war ii. During the buildup, air corps leaders reevaluated the value of pursuit as they witnessed the air battles between major powers in europe and the pacific.