The Willys MB (commonly known as a Jeep or jeep, formally as the U.S. Army Truck, 1/4 ton, 4x4) and the Ford GPW are four-wheel drive utility vehicles that were manufactured during World War II. Produced from 1941 to 1945, it evolved post-war into the civilian Jeep CJ, and inspired both an entire category of recreational 4WDs and several generations of military light utility vehicles.
Advances in early 20th-century technology resulted in widespread mechanisation of the military during World War I. The United States Army deployed four-wheel drive trucks in that war, supplied by Four Wheel Drive Auto (FWD) and the Thomas B. Jeffery Company. By the eve of World War II the United States Department of War had determined it needed a light, cross-country reconnaissance vehicle.
Anxious to have one in time for America's entry into World War II, the U.S. Army solicited proposals from domestic automobile manufacturers for a replacement for its existing, aging light motor vehicles, mainly motorcycles and sidecars, and some Ford Model T's. Marmon-Herrington presented five 4×4 Fords in 1937, and American Bantam delivered three Austin roadsters in 1938. Recognizing the need to create standard specifications, the Army formalized its requirements on July 11, 1940, and submitted them to 135 U.S. automotive manufacturers.