In 1935, the year of the B-17 Flying Fortress' maiden flight, the USAAC already wanted to develop a potential successor. Bigger, faster, and with a much heavier bombload, the B-19 was planed to be the world's first intercontinental bomber, able to fight future air wars from American soil. After six years of development, Douglas' prototype XB-19 would be the world's largest aircraft when it finally flew in June 1941, with an all-up weight of 81 tons. While the XB-19 never flew in combat, its lengthy development taught American aero engineers many lessons about designing and building such huge aircraft, and its flight-test career as a "Flying Laboratory" significantly influenced the development of the B-36 Peacemaker, the world's first true intercontinental bomber. Based on original USAAF aircraft acceptance documents, first-hand narratives of its maiden flight, and other USAAC and Douglas Company documents, this book provides a superbly illustrated history of the XB-19 intercontinental bomber, with rare photographs and spectacular new artwork. Throughout the last century, one-off experimental aircraft and cutting-edge military prototypes have pushed the boundaries of what is possible. Authoritative and accessible, X-Planes is the series that explains the technology behind the world's most important prototype and research aircraft, their often dangerous flight-test careers, and how their successes and failures influenced frontline aircraft development. Each Book Contains: The best archive photography, Meticulously detailed original artwork, Expert history and analysis Book jacket.