
The Willys MB and the Ford GPW, both formally called the U.S. Army Truck, 1⁄4-ton, 4×4, Command Reconnaissance, commonly known as Jeep and sometimes referred to as G503 were highly successful off-road capable, light, military utility vehicles, built in large numbers to a standardized design, from 1941 to 1945, for the Allied forces in World War II.
Source: http://jeepwillys73.overblog.com/