Willys-Overland was the second largest automobile producer in the United States in the early 20th century. Surpassed only by Ford, Willys-Overland was successful until the Depression era affected the market.

It was on this day, November 13th, in 1940 that Willys-Overland submitted the Jeep prototype to the U.S. Army. By 1945, over 600,000 Jeeps had already been manufactured.

The War Department asked several automakers to produce a lightweight truck for military use. The automobile’s true name is “General Purpose,” or GP for short. The current name, Jeep, is thought to be a phonetic spelling of the abbreviation GP. A Popeye comic strip first documented the name Jeep, and it has stuck ever since.