Pointblank. The Operation Overlord air plan for the strategic bombing of both Germany and German military forces in continental Europe prior to the 1944 invasion of France used several Air Forces, primarily those of the USAAF and those of the Royal Air Force (RAF), with the command of air operations transferring to the Supreme Commander of the Allied Expeditionary Force on 14 April 1944. Planning to reorganize for a separate and independent postwar U.S. Air Force had begun by the fall of 1945, with the Simpson Board tasked to plan, "...the reorganization of the Army and the Air Force...". In January 1946, Generals Eisenhower and Spaatz agreed on an Air Force organization composed of the Strategic Air Command, the Air Defense Command, the Tactical Air Command, the Air Transport Command and the supporting Air Technical Service Command, Air Training Command, the Air University, and the Air Force Center. Establishment and transfer to USAF Strategic Air Command was originally established in the U.S. Army Air Forces on 21 March 1946, acquiring part of the personnel and facilities of the Continental Air Forces (CAF), the World War II command tasked with the air defense of the continental United States (CONUS). At the time, CAF headquarters was located at Bolling Field (later Bolling AFB) in the District of Columbia and SAC assumed occupancy of its headquarters facilities until relocating SAC headquarters (HQ SAC) to nearby Andrews Field (later Andrews AFB), Maryland as a tenant activity until assuming control of Andrews Field in October 1946. SAC initially totaled 37,000 USAAF personnel. In addition to Bolling Field and, seven months later, Andrews Field, SAC also assumed responsibility for: Roswell AAF, New Mexico (later renamed Roswell AFB, then Walker AFB), then home of the USAAF's sole nuclear-capable bomb wing, and Smoky Hill AAF, Kansas (later renamed Smoky Hill AFB, then Schilling AFB) SAC also had seven additional CAF bases transferred on 21 March 1946 which remained in SAC through the 1947 establishment of the U.S. Air Force as an independent service. Those installations included: Castle Field, California (later Castle Air Force Base) Clovis AAF, New Mexico (later Cannon Air Force Base) Fort Worth AAF, Texas (later Carswell Air Force Base) Davis-Monthan Field, Arizona (later Davis-Monthan Air Force Base) Rapid City AAF, South Dakota (later Ellsworth Air Force Base) MacDill Field, Florida (later MacDill Air Force Base) Mountain Home AAF, Idaho (later Mountain Home Air Force Base)