Hummer's a brand of off-road vehicles sold by General Motors (GM). The original Hummer H1 was based on the military High Mobility Multipurpose Wheeled Vehicle (HMMWV, or Humvee). However, the Hummer H2 and the Hummer H3 were based on other, smaller civilian-market vehicles. History Hummers were originally built by AM General Corporation, which was formerly AMC Jeep's General Products division, in its Mishawaka, Indiana assembly plant. They were created under a contract for the United States arm… (More on Hummer)