Like all chronologies, bibliographies, and encyclopedias, Air Force Combat Units of World War II serves a very special historical function. It traces the lineage of each Army Air Corps and U.S. Air Force combat group or higher organization active in World War II, from its origins to 1956. It is a concise official record of those units: their assignments, subordinate organizations, stations, commanders, campaigns, aircraft, and decorations. But it is more than that. As an important source of ready information, this volume not only serves as a reference tool for historians and researchers; but it also provides commanders with a corporate memory of vital statistics. With these facts, a unit documents its heritage, the basis for unit esprit de corps. Originally this volume had been printed in 1961. Its worth has been proven, and the demand for it has been great. With this reprint, it will continue to serve the United States Air Force in all quarters in years to come.