The first jeep prototype was invented in what year?

The first jeep designed and built in America was in 1940. Karl Probst (October 1883 - August 1963) was an American freelance engineer and automotive pioneer. He is credited with building the first jeep prototype.

Probst was recruited by American Bantam Car Company in 1940 to help it win a contract to provide the U.S. Army with a lightweight reconnaissance vehicle that could transport troops and equipment across rugged terrain. Probst drafted the design for the Jeep in two days. Commencing on June 17, 1940, Bantam's first hand-built prototype was complete and running by September 21, 1940, just meeting a 49 day deadline. The jeep was then delivered to the Army Quartermaster Corps for testing at Camp Holabird, MD.

Willys MB Jeeps went into production in 1941. They were made specifically for the military, arguably making them the oldest four wheel drive mass production vehicles now known as SUVs.

The first civilian models were produced in 1945.