Book is compilation of all United States pilots, observers, gunners and mechanics who flew against the enemy in WWI. Covered are Americans who flew with French and British air services, U.S. Navy aviators, the 103rd Pursuit Squadron, the 1st Balloon Group, the 1st Pursuit Group, the 1st Corps Observation Group, American bomber units, the 2nd Pursuit Squadron, the 3rd Pursuit Group, and all other units in which Americans flew.