AM General was the heavy industries division of American Motors. It became an independent company in 1982 when AMC wanted to sell controlling interest of itself to Renault. Government regulations forbade ownership of defense contractors by foreign governments, and Renault was partially owned by the French government.

AM General produced buses, large trucks, and jeeps for industrial, military, and government use. In the late 1970s, it developed the High Mobility Multipurpose Wheeled Vehicle for military use as a heavy-duty replacement for the jeep. The vehicle later became available in a civilian version sold under the Hummer brand name.

AM General, who remains an independent company and government and military contractor, sold the rights to the HUMMER name to General Motors in 1999. AM General continues to build the vehicles for GM, who was sued early in 2003 by DaimlerChrysler, then owners of the Jeep brand, for the HUMMER's resemblance to the Jeep.

On August 20, 2004, it was announced that Ronald Perelman's MacAndrews & Forbes Holdings company would form a joint venture with AM General's current owner, Renco Group, to give Perelman 70% ownership of AM General. The deal reportedly cost close to US$1,000,000,000.