This collection of squadron histories has been prepared by the USAF Historical Division to complement the Division's book, Air Force Combat Units of World War II. The 1,226 units covered by this volume are the combat (tactical) squadrons that were active between 7 December 1941 and 2 September 1945. Each squadron is traced from its beginning through 5 March 1963, the fiftieth anniversary of the organization of the 1st Aero (later Bombardment) Squadron, the first Army unit to be equipped with aircraft for tactical operations. For each squadron there is a statement of the official lineage and data on the unit's assignments, stations, aircraft and missiles, operations, service streamers, campaign participation, decorations, and emblem.