It was the largest aircraft built by the US at the time, with a span of 212 ft, a length of 132 ft, and a height of 42.9 ft, a record it would hold until 1946. It had an impressive armament, including two .37 mm cannons, five .50 caliber machine guns, six .30 caliber machine guns, and a capacity of 18,700 lbs of bombs.
The XB-19's first flight occurred on June 27, 1941. Only one was ever built, which was mainly used for testing construction methods that could make the building of large aircraft easier. After the tests, the aircraft was redesignated XB-19A and used as a tranpsort aircraft through the end of the war. It was scrapped in 1949.