In July 1940, the American military told auto-makers that it was looking for a 'light reconnaissance vehicle' to replace the army's motorcycle and modified Ford Model-T vehicles.

The army invited 135 manufacturers to bid on production and developed a lengthy specification list for the vehicle, including four-wheel drive with two-speed transfer case, a fold-down windshield, three bucket seats and blackout and driving lights.

At first, Willys-Overland and American Bantam Car Manufacturing Company were the only two companies answering the call. Soon, however, Ford Motor Company entered the competition for the lucrative government contract. Each produced prototypes for testing in record time, delivering them to the army in summer 1940 and received approval to build 70 sample vehicles.

The Army realised the original 1,300lb limit was too low and raised it for the next round of contracts in March 1941. Bantam was to produce 1,500 Model 40 BRCs, Ford 1,500 modified and improved Model GP (General Purpose) models, known as the Pygmy, and Willys 1,500 Quads. Further testing and evaluation led to the army's selection of Willys vehicle as the primary manufacturer and, subsequently, most of the Bantams and Ford GPs were to Great Britain and Russia as part of the lend-lease program.

With modifications and improvements, the Willys Quad became the MA, and later the MB, but the army, and the world, came to know it as the Jeep. Some claimed the name came from the slurring of the letters GP, the military abbreviation for General Purpose, others say it was after popular character Eugene the Jeep in the Popeye cartoon strip.

Willys-Overland would build more than 368,000 vehicles, and Ford, under licence, some 277,000 for the US Army.

Willys trademarked the Jeep name after the war and planned to turn the vehicle into an off-road utility vehicle for the farm – the civilian Universal Jeep.

Here are some key historical civilian Jeeps:

Jeep CJ-2A, 1945-1949

The first civilian Jeep vehicle came with a tailgate, side-mounted spare tyre, larger headlights, an external fuel cap and many more items that its military predecessors did not include. Several CJ-2A mechanical features were found on numerous Jeep vehicles in future years. The CJ-2A was produced for four years.

Jeep Pick-up, 1947-1965

This pick-up was Willys-Overland's first bid to diversify the Jeep brand from the CJ.

Jeep Jeepster, 1948-1951

The last phaeton-style open-bodied vehicle made by an American automaker, using side curtains for weather protection instead of roll-down windows.

Jeep CJ-5, 1955-1983

In 1953, Willys-Overland was sold to Henry J Kaiser for $60m and the Kaiser Company began extensive research and development that would broaden the Jeep product range. In 1955, it introduced the CJ-5, based on the 1951 Korean War M-38A1, with softer, more rounded styling. It was slightly larger than the CJ-3B and improved engines, axles, transmissions and seating comfort made it an ideal vehicle for the public's growing interest in off-road vehicles.

Willys Wagon, 1946-1965

This wagon was long an enthusiast favorite. Four-wheel drive was introduced in 1949.

Jeep Wagoneer, 1963-1983

The 1963 Jeep Wagoneer was the first four-wheel-drive vehicle mated with an automatic transmission, pioneering the first modern sport utility vehicle. Quadra-Trac, the first automatic full-time four-wheel-drive system, was introduced in 1973 and available in full-size Jeep trucks and wagons.

Jeep Cherokee (SJ), 1974-1983

The two-door Cherokee, aimed at a younger demographic than the Wagoneer, was built for the growing recreational vehicle market. It was marketed as an off-road vehicle more than the Wagoneer.

Jeep CJ-7, 1976-1986

American Motors Corporation (AMC) introduced the CJ-7, the first major change in Jeep design in 20 years. The CJ-7 had a slightly longer wheelbase than the CJ-5 in order to allow space for an automatic transmission. For the first time, the CJ-7 offered an optional molded plastic top and steel doors.

Jeep Grand Wagoneer, 1984-1991

The Grand Wagoneer marked the beginning of the luxury SUV, giving buyers an unheard-of combination of standard features such as leather upholstery, air conditioning, AM/FM/CB stereo radios, added sound insulation and wood-grain exterior trim.

Jeep Cherokee (XJ), 1984-2001

AMC's first Jeep design from scratch, and the first all-new Jeep wagon since the Wagoneer. New Quadra-Link front suspension retained the durability of a solid front axle while improving ride and handling. Available with two 2WD/4WD drive systems – SelecTrac and shift-on-the-fly CommandTrac, and four doors – Cherokee dominated its market segment for years.

Jeep Wrangler (YJ), 1987-1996

In 1983, the growing market for compact four-wheel-drive vehicles still sought the utilitarian virtues of the Jeep CJ series, but consumers also were seeking more passenger car creature comforts. In comes the Wrangler, out goes the CJ.

In 1987, American Motors Corporation was sold to the Chrysler Corporation and the Jeep brand became a part of Chrysler's Jeep/Eagle Division.

Jeep Grand Cherokee (ZJ/WJ), 1993-2004

The Grand Cherokee famously first appeared by crashing through the convention center glass at the North American International Auto Show in Detroit during its introduction in 1992. The first SUV equipped with a driver's side air bag, it set new standards for on-road ride, handling and comfort in an SUV.

Jeep Wrangler and Wrangler Unlimited (JK), 2007-present

The JK delivers more capability, refinement, interior space and comfort, open-air fun, power, fuel efficiency and safety features.

Featuring a one-of-a-kind, four-door open-air design, it was the first Wrangler with room for five adults and had the most cargo space ever.