In 1940 Henry Stimson, the US Secretary of War, and General George Marshall, the Chief of Staff of the US Army, decided to reorganize the air force. The Air Corps that had been responsible for training and procurement, and the Air Force Combat Command, were merged to become the United States Army Air Forces (USAAF). General Henry Arnold was appointed as commander of the USAAF.
This USAAF suffered badly during the Japanese Air Force attack on Pearl Harbor on 7th December, 1941. A total of 178 aircraft were destroyed on the ground and 159 were damaged. An estimated 2,403 men were killed and a further 1,778 were injured.
After the United States entered the Second World War aircraft production rose dramatically. In 1942 10,769 fighters and 12,627 bombers were built. The following year this was increased to 23,988 fighters and 29,355 bombers. The peak was reached in 1944 with 38,873 fighters and 35,003 bombers being built.
This included new fighters such as the P-51 Mustang, the Grumman Hellcat, the Chance-Vought Corsair and the Republic Thunderbolt. Dramatic improvements also took place in the production of US bombers such as the B-17 Flying Fortress, the B24 Liberator and the B-29 Stratafortress.
In February 1942, Air Marshall Arthur Harris, the new head of RAF Bomber Command, decided to adopt the Nazi policy of area bombing (known in England as terror bombing) where entire cities and towns were targeted. The US 8th Air Force, based in southern England, played an important role in this strategic bombing offensive.
Whereas the Royal Air Force bombed German cities at night the USAAF under the command of General Carl Spaatz used its B-17 Flying Fortress and B24 Liberator aircraft for precision daylight operations. In August 1943 repeated incendiary attacks on Hamburg caused a firestorm and 50,000 German civilians were killed.
In early 1944 the USAAF introduced the long-range Mustang P-51B fighter. This new aircraft could escort bombers all the way to targets deep inside Nazi Germany. It was an outstanding combat plane and inflicted considerable damage on the Luftwaffe.
Despite objections from Arthur Harris and Carl Spaatz, the bombing campaign changed during the summer of 1944. As part of Operation Overlord, the task of the RAF and the USAAF was to destroy German communications and supply lines in Europe. The destruction of German oil production was also made a priority target and by September, 1944, the Luftwaffe's fuel supply had been reduced to 10,000 tons of octane out of a monthly requirement of 160,000 tons.
By the end of 1944 the Allies had obtained complete air supremacy over Germany and could destroy targets at will. On 3rd February, 1,000 bombers of the USAAF killed an estimated 25,000 people in Berlin.
Arthur Harris now devised Operation Thunderclap, an air raid that would finally break the morale of the German people. To enable maximum impact to take place Harris chose Dresden as his target. This medieval city had not been attacked during the war and was virtually undefended by anti-aircraft guns. On 13th February 1945, 773 Avro Lancaster bombers attacked Dresden. During the next two days the USAAF sent 527 heavy bombers to follow up the RAF attack. The resulting firestorm killed around 135,000 people.
Tokyo , the capital of Japan was a major target of the USAF during the Second World War. The first raids began in late 1944 when the new B-29 Stratafortress heavy bombers began operating from bases in the Mariana Islands.
After the US Army captured Iwo Jima the USAF was able to use the island to increase its bombing attacks on Japan. The large number of Japanese buildings made of wood made it easy for the bombers to create firestorms. On the 9th and 10th March 1945, a raid on Tokyo devastated the city. This was followed by attacks on Nagoya, Kobe, Oska and Yokohama. An estimated 260,000 were killed and 9.2 million left homeless.
By the summer of 1945 the USAAF was ready to mount its final strategic bombing campaign. On 6th August 1945, a B-29 Stratafortress bomber dropped an atom bomb on Hiroshima. Japan continued to fight and a second bomb was dropped on Nagasaki three days later. On 10th August the Japanese surrendered. The Second World War was over.
The peak wartime strength of the USAAF was 75,000 aircraft and 2,411,294 personnel. The total wartime casualties amounted to 115,382. This included the deaths of 52,173 pilots and aircrew.