The XB-59 was an aircraft that was build out of the XB-55 program. Building the XB-55 was meant to replace the Boeing B-47. But as soon as the B-47 got its momentum back, development of the XB-55 program was terminated and its funds were transferred to XB-59’s development.

Despite the increased production of the B-47; the Air Force needed an intercontinental, supersonic bomber. The Army Air Force wanted design parameters of a 10,000 lbs. bomb load, a radius of 1200 to 2500 miles and a takeoff distance of less than 6000 feet. 

Boeing submitted the winning proposal, and a Phase I contract for the XB-55 was initiated with FY 1948 funds. It it’s design, there was a pressurized cabin for the three man crew and a remote controlled tail turret gun. The design featured four jet engines located inside the inboard wing. Engines included the Pratt & Whitney J57 and the General Electric J73. All the fuel of the aircraft was carried inside the fuselage. 

In response to the Air Force's request of such bomber, Convair was also producing an aircraft, known as the XB-58. By the end of 1950, the Bombardment Branch of the Air Materiel Command's Aircraft and Guided Missiles Section began to prepare a detailed military specification for both the Boeing and Convair proposals. Based on the AMC proposal, which was in turn based on input from both the Boeing and Convair design studies, requests were made for funds for beginning projects. 

For some time, the Air Force funded both projects but as financing became difficult due to budget constrain, by the Summer of 1952, the Air Force concluded that it would fund only one of the two designs Convair's XB-58 was chosen as Boeing's design offered insufficient supersonic capabilities.

On November 18, 1952 Convair was officially named the winner of the development contest and XB-59 production was canceled.