American World War 2 planes weren’t seen in combat at the beginning of the conflict. Two years after the outbreak of WW2, the USA declared war to the Axis powers after the bombing of Pearl Harbor by the Japanese aviation on December 7, 1941. During these two years, though, the country of the Wright brothers manufactured and sold tons of material (including airplane engines and parts) to the Allied Forces, mainly Britain and the Commonwealth countries like Australia, Canada or New-Zealand, which all were put in contribution as early as 1939. Besides, several American pilots went fighting in Europe on a voluntary basis in Britain aircrafts.
After the raid that saw hundreds of Japanese aircrafts basically destroy the Pearl Harbor fleet and many of the Air Force bases of the island, the war effort went into full swing and, ultimately, the engagement of the U.S. made the difference.
We can say that the attack on Hawaii was the sting that woke up the giant. Thanks to their determination and their enormous economic power, the American people changed the course of the war, producing some of the best airplanes of the time.
Building aircraft like hell
Several combat aircrafts were designed and built in the USA. Among the most famous, we can think of the P-51 Mustang, the F4U Corsair, and the B-29 Superforteress, which is remembered as the airplane that dropped the atomic bomb on the Japanese city of Hiroshima on August 6, 1945, and would later constitute the backbone of the strategic bomber command, the deterance arm of US military aviation.