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 the Willys Jeep, Jeep, or jeep, and sometimes referred to as G503,[nb 3] were highly successful American off-road capable light military utility vehicles built in large numbers to a standardized design for the United States and other Allied forces in World War II from 1941 to 1945.
The jeep became the primary light wheeled transport vehicle of the United States military and its allies, with President Eisenhower once calling it "one of three decisive weapons the U.S. had during WWII." It was the world's first mass-produced four-wheel drive car, manufactured in six-figure numbers; almost 650,000 units were built, constituting a quarter of the total U.S. non-combat motor vehicles produced during the war,[nb 4] and almost two-thirds of the 988,000 light 4WD vehicles produced, counted together with the Dodge WC series. Large numbers of jeeps were provided to U.S. allies, including Russia at the time — aside from large amounts of 11⁄2- and 21⁄2-ton trucks, some 50,000 1⁄4-ton jeeps and 25,000 3⁄4-ton Dodges were shipped to Russia during WWII — more than Nazi Germany's combined total production of their best performing similar vehicles, the Kübelwagen and the amphibious Schwimmwagen.
Historian Charles K. Hyde wrote: "In many respects, the jeep became the iconic vehicle of World War II, with an almost mythological reputation of toughness, durability, and versatility." Not only did it become the workhorse of the American military, as it replaced the use of horses and other draft animals (still heavily used in World War I) in every role, from cavalry units to supply trains, but improvised field modifications also made the jeep capable of just about any other function GIs could think of.
The jeep was considered such a valuable vehicle that General Eisenhower wrote that most senior officers regarded it as one of the five most vital pieces equipment to success in Africa and Europe[nb 5] Moreover, General George Marshall called the squared-off little car "America's greatest contribution to modern warfare." In 1991, the MB Jeep was designated an "International Historic Mechanical Engineering Landmark" by the American Society of Mechanical Engineers.
After WWII, the original jeep continued to serve, in the Korean War and other conflicts, until it was updated in the form of the M38 Willys MC and M38A1 Willys MD (in 1949 and 1952 respectively), and received a complete redesign by Ford in the form of the 1960-introduced M151 jeep. Its influence, however, was much greater than that — manufacturers around the world began building jeeps and similar designs, either under license or not — at first primarily for military purposes, but later also for the civilian market. Willys trademarked the "Jeep" name, turned the MB into the civilian Jeep CJ models, and Jeep became its own brand. The 1945 Willys Jeep was the world's first mass-produced civilian four-wheel drive car.
The success of the jeep inspired both an entire category of recreational 4WDs and SUVs, making "four-wheel drive" a household term, and numerous incarnations of military light utility vehicles. In 2010, the American Enterprise Institute called the jeep "one of the most influential designs in automotive history". Its "sardine tin on wheels" silhouette and slotted grille are perhaps even more instantly recognizable than the VW Beetle and has evolved into the currently produced Jeep Wrangler long after the demise of the original Jeep design.