The Willys MB US Army Jeep (formally the Truck, 1/4 ton, 4x4) and the Ford GPW, was manufactured from 1941 to 1945. The small four-wheel drive utility vehicles are considered the iconic World War II Jeep, and inspired many similar light utility vehicles. Over the years, the World War II Jeep later evolved into the "CJ" civilian Jeep. Its counterpart in the German army was the Volkswagen Kübelwagen, also based on a small automobile, but which used an air-cooled engine and lacked 4 wheel drive.
During World War I there were limited attempts to mechanize military forces. The US Army had already used 4x4 trucks supplied by the Four Wheel Drive Auto Co. (FWD). By the time of World War II, the United States Department of War was still seeking a light, cross-country reconnaissance vehicle.
As tensions were heightening around the world in the late 1930s, the U.S. Army asked American automobile manufacturers to tender suggestions to replace its existing, aging light motor vehicles, mostly motorcycles and sidecars but also some Ford Model T's. This resulted in several prototypes being presented to army officials, such as five Marmon-Herrington 4x4 Fords in 1937, and three Austin roadsters by American Bantam in 1938 (Fowler, 1993). However, the US Army's requirements were not formalized until July 11, 1940, when 135 U.S. automotive manufacturers were approached to submit a design conforming to the army's specifications for a vehicle the World War II training manual TM 9-803 described as "... a general purpose, personnel, or cargo carrier especially adaptable for reconnaissance or command, and designated as 1/4-ton 4x4 Truck."
By now the war was underway in Europe, so the Army's need was urgent and demanding. Bids were to be received by July 22, a span of just eleven days. Manufacturers were given 49 days to submit their first prototype and 75 days for completion of 70 test vehicles. The Army's Ordnance Technical Committee specifications were equally demanding: the vehicle would be four-wheel drive, have a crew of three on a wheelbase of no more than 75 (later 80) inches and tracks no more than 47 inches, feature a fold-down windshield, 660 lb payload and be powered by an engine capable of 85 ft·lbf (115 N·m) of torque. The most daunting demand, however, was an empty weight of no more than 1,300 lb (590 kg).
Only three companies entered: American Bantam Car Company, Ford Motor Company and Willys-Overland Motors. Though Willys-Overland was the low bidder, Bantam received the bid, being the only company committing to deliver a pilot model in 49 days and production examples in 75. Under the leadership of designer Karl Probst, Bantam built their first prototype, dubbed the "Blitz Buggy" (and in retrospect "Old Number One"), and delivered it to the Army vehicle test center at Camp Holabird, Maryland on September 23, 1940. This presented Army officials with the first of what eventually evolved into the World War II U.S. Army Jeeps: the Willys MB and Ford GPW.