Saw this trio of postal jeeps parked behind a post office in Corrales. While they weren't dripping with custom panache they're good examples of the iconic American off-roader.
The Jeep was originally developed by the Bantam car company in response to a call from the government for a lightweight scout vehicle. Bantam developed the original prototype but the government licensed the design to Willys and Ford to actually produce (thinking that Bantam was not large enough to build them in the quantities needed). The distinctive stamped grill was actually added by Ford, and kept by the Army for the production vehicles.
Willys was the only manufacturer to continue building the jeep after the war, and were given the trademark for the name because of that. The brand went through many owners before ending up with Chrysler.
It is commonly believed that the name comes from the Army's original designation of General Purpose or GP vehicle. The original Bantam prototype was called the Bantam Reconnaissance Car or BRC; imagine if the iconic American 4x4 had been called the Brick!