The North American Aviation Company began work on a new bomber, the B-25A Mitchell in 1938. The aircraft was named after William Mitchell, the leading figure in the USA Air Service during the First World War.

The first of these aircraft were delivered to the United States Air Force in 1941. It had a maximum speed of 315 mph (507 km) and had a range of 1,350 miles (2,170 km). It was 54 ft 1 in (16.48 m) long with a wingspan of 67 ft 7 in (20.60 m). The aircraft was armed with 5 machine-guns and could carry 3,000 lb (1,360 kg) of bombs.

The aircraft was constantly modified. The final version, B-25J Mitchell, appeared in 1944. Probably the best medium sized bomber of the Second World War, it was also used by the Royal Air Force and the Red Army Air Force. The aircraft completed 63,177 missions and dropped 84,980 tons of bombs on Nazi Germany. It was also used extensively in the Pacific War.