The Allison Engine Company was an American aircraft engine manufacturer. Shortly after the death of James Allison in 1929 the company was purchased by the Fisher brothers. Fisher sold the company to General Motors, which owned it for most of its history. It was acquired by Rolls-Royce plc in 1995 to become the US subsidiary, Rolls-Royce North America.

General Motors Company (GM) is an American multinational automotive manufacturing company headquartered in Detroit, Michigan, United States. The company is most known for owning and manufacturing four automobile brands, Chevrolet, GMC, Cadillac and Buick. By sales, it was the largest automaker in the United States in 2022, and was the largest in the world for 77 years before losing the top spot to Toyota in 2008.