Boeing created the Model 400 in response to the US Navy’s need for a fighter-bomber capable of long-range flights from carriers. On May 4, 1943, the Navy awarded the company a contract to produce three prototypes, which resulted in the XF8B-1 aircraft. Although the XF8B-1 was primarily designed for fighting purposes, it was also built to carry an internal bomb load of over 3,000 pounds (1,360 kilograms) and could accommodate a similar external payload. If the XF8B-1 had entered production, it would have likely been reclassified as an attack aircraft.