The first aircraft named using just a B- designation. Prior to 1926, the U.S. Army used LB- and HB- prefixes, signifying 'Light Bomber' and 'Heavy Bomber'. The first XB-1, called the Super-Cyclops by Huff-Daland, was an extension of the earlier Huff-Daland XHB-1 'Cyclops'. It was essentially the same in size, but sported a twin tail and twin engines. Its gunnery arrangement was new for an American bomber, but it had been previously used by the British and the Germans near the end of World War I. The Army Air Corps had decided that single engined bombers such as the XHB-1 performed more poorly and with less safety than the more traditional twin-engined bomber. The aircraft flew for the first time in 1927 September.
Its original Packard engines did not provide enough power for the plane, and it was refitted with more powerful Curtiss Aircraft 'Conqueror' engines. This new configuration was designated the XB-1B.
Three other similar planes were requested by the Army Air Corps around the same time which competed against the XB-1 for the contract. Of these three (the Curtiss XB-2 Condor, the Sikorsky S-37, and the Fokker XLB-2), the Curtiss model eventually won, and only a single XB-1 was ever produced.