after the fall of france, during 1940–1941, approximately 4,800 experienced national guard aviation personnel were mobilized from their observation squadrons. they provided a significant augmentation of the army's rapidly expanding air arm during a critical period. most guard air units were stripped of many key personnel, and the units were federalized into the regular army air corps and were re-equipped with more modem aircraft. some of the early-deploying squadrons maintained a degree of unit integrity and cohesion. but, most lost their character and identity as guard organizations during world war ii.