At its inception, the B-24 was a modern design featuring a highly efficient shoulder-mounted, high aspect ratio Davis wing. The wing gave the Liberator a high cruise speed, long range and the ability to carry a heavy bomb load. Early RAF Liberators were the first aircraft to cross the Atlantic Ocean as a matter of routine. In comparison with its contemporaries the B-24 was relatively difficult to fly and had poor low speed performance; it also had a lower ceiling and was less robust than the Boeing B-17 Flying Fortress. While aircrews tended to prefer the B-17, General Staff favored the B-24, and procured it in huge numbers for a wide variety of roles. At nearly 19,000 units – including over 8,000 manufactured by Ford Motor Company – it holds records as the world's most produced bomber, heavy bomber, multi-engine aircraft, and American military aircraft in history.
The B-24 was used extensively in World War II. It served in every branch of the American armed forces, as well as several Allied air forces and navies, and saw use in every theater of operations. Along with the B-17, the B-24 was the mainstay of the U.S. strategic bombing campaign in the Western European theater. Due to its range, it proved useful in bombing operations in the Pacific, including the bombing of Japan. Long range anti-submarine Liberators played an instrumental role in closing the Mid-Atlantic gap in the Battle of the Atlantic. The C-87 transport derivative served as a longer range, higher capacity counterpart to the Douglas C-47 Skytrain.
By the end of World War II, the technological breakthroughs of the Boeing B-29 Superfortress and other modern types had surpassed the bombers that served from the start of the war. The B-24 was rapidly phased out of U.S. service, although the PB4Y-2 Privateer maritime patrol derivative carried on in service with the U.S. Navy in the Korean War.
The Liberator originated from a United States Army Air Corps (USAAC) request in 1938 for Consolidated to produce the B-17 under license. After company executives including President Reuben Fleet visited the Boeing factory in Seattle, Washington, Consolidated decided instead to submit a more modern design of its own.
The new Model 32 combined designer David R. Davis's wing, a high-efficiency airfoil design created by unorthodox means, with the twin tail design from the Consolidated Model 31 flying boat, together on a new fuselage. This new fuselage was intentionally designed around twin bomb bays, each one being the same size and capacity of the B-17 bomb bays.