This study traces the evolution of the F-15 Eagle air superiority fighter from its beginning in 1964 through the aircraft's first flight in July 1972. It examines the military, technological, economic, and political influences on the weapon system acquisition process. Among the more innovative elements of this research and development program were: the energy maneuverability theory of Col. John R. Boyd and Thomas Christie; a contractual arrangement loosely billed as the "fly-before-buy" philosophy; and the definite Air Force commitment to building the aircraft first manifest in the appointment of Brig. Gen. Roger K. Rhodarmer as Washington F-15 spokesman. then through the support given Maj. Gen. Benjamin N. Bellis, the F-15's strong program director. The story ends with air superiority reaffirmed as a major mission, but not yet fully defined.