North American Aviation
It was founded in 1928 to buy airlines, but then was forced to give up its control of those airlines because of the Air Mail act of 1934. It then went into manufacturing. The first plane it built was the T-6 Texan. It also built the B-25 Mitchell, the P-51 Mustang, and the F-86 Sabre. It later became part of Boeing after a series of mergers.