The Frenchman who founded the city of Detroit and discovered Louisiana for France, the luxury car, Cadillac is named in honor of him.
Antoine de la Mothe Cadillac was born in 1658 near Toulouse, France. In 1683, Cadillac arrived in North America and settled at Port Royal in Nova Scotia, subsequently several years later the French king awarded him six square miles of land at what is now Bar Harbor, Maine, and also Mount Desert Island.
In July 1701, Detroit was founded with erection of Fort Ponchartrain by an expedition led by Cadillac. After returning to France in 1711 (Despite being requested to go to Louisiana) he returning to the American continent (Louisiana) in June 1713 and was subsequently made Governor of Louisiana, the largest amount of land ever ruled by any governor in America.
A scant 3 years later, Cadillac fell on financial troubles and was deposed, tried, and sentenced to the Bastile for 5 months. His last years were spent as Governor of Castelsarrasin (Appointed 1722), in Southern France and there he died in 1730.
Sources
http://www.car-nection.com/yann/dbas_txt/Coatarms.htm