The United States had to create for itself, after entering the war, not only the new arm of air warfare almost from its very foundation, but also the industry for its development and support. Much controversy raged over the Government’s air program and its progress during almost the entire year and a half and many and loud and long-continued were the charges of inefficiency, incompetence and failure. Mistakes there were, since human beings have not yet ceased the making of them, but when America’s achievement in air warfare is considered in all its phases and as a whole the frank and fair judgment can not fail to be that her development of the air section of her fighting forces deserves to rank among the most notable of all her wartime achievements. In April, 1917, this country had in the Aviation Section of the Signal Corps two small and poorly equipped flying fields, sixty-five officers, 1,120 men and less than 300 second rate planes, most of them for training, and there were ready for its use comparatively few of the many and varied manufacturing industries and the trained workmen necessary for the development of an extensive war aviation program. Nor was there any one who had more than a vague appreciation of the complicated technique that would be required for such a development. Although aviation had been born in the United States it had not received here the interest and commercial encouragement necessary for its growth and had had to betake itself to Europe to find the means and the opportunity for development. This lack of commercial interest had been reflected in the army and a conservative General Staff had given only the slightest consideration to the military possibilities of aircraft. Not until the summer of 1914 had an aviation section been incorporated in the army and there had been very little increase or betterment in its facilities during the following two and a half years. Even after our declaration of war an important aircraft participation was not contemplated by the General Staff until it was asked for by our war associates.