The Consolidated B-24 Liberator was an American heavy bomber, designed by Consolidated Aircraft Company. The B-24 ended World War II as the most produced Allied heavy bomber in history, and the most produced American military aircraft in history at over 18,400 units.
The B-24 was used by several Allied air forces and navies, and by every branch of the American armed forces during the war, attaining a distinguished war record with its operations in the Western European, Pacific, Mediterranean, and China-Burma-India Theaters.
Often compared with the better-known B-17 Flying Fortress, the B-24 was a more modern design with a higher top speed, greater range, and a heavier bomb load; however, it was also more difficult to fly, with heavy control forces and poor formation-flying characteristics. Popular opinion among aircrews and general staffs tended to favor the B-17's rugged qualities above all other considerations in the European Theater. Nevertheless, the B-24 provided excellent service in a variety of roles thanks to its large payload and long range.
The B-24's most infamous mission was the low-level strike against the Ploiești oil fields, in Romania on 1 August 1943, which turned into a disaster because the enemy was underestimated, fully alerted and attackers disorganized.
Source: Wikipedia, "Consolidated B-24 Liberator", available under the CC-BY-SA License.