The MB-3A contract was the government's largest order for new airplanes since the end of WWI. After underbidding the designer, the Thomas-Morse Aircraft Corp., Boeing won the contract to build 200 of the single-seat fighters. The MB-3A was a conventional wood-and-wire fabric-covered fighter derived from the French Spad of WWI. Boeing delivered all 200 MB-3As by the end of 1922 and established itself as a reliable manufacturer of fighter aircraft.