CADILLAC, Antoine de la Mothe, founder of Detroit, born in Gascony, France, about 1660; died after 1717. He was of noble birth, served in Acadia as a captain in the French army, and in 1680 was ordered to France by Louis XIV. to furnish information relative to New France and the English colonies, and especially to the condition of the harbors and defenses on the coast. He was made lord of Bouagnat and Mount Desert, Maine, in 1691, and in 1694 Frontenac appointed him commander of Michilimackinac, then the largest place in Canada, next to Montreal and Quebec. He remained here until 1697, and in 1699 laid before the king at Versailles his plan of establishing a permanent post to become the commercial centre of the northwest. The king favored the project; but on his return to Canada Cadillac met with discouragement from the governor-general. Landing finally at Detroit, 24 July, 1701, with fifty settlers and fifty soldiers, instead of the 200 settlers and six companies that he had been promised by the king, he laid the foundations of the present City, which he named Fort Pontchartrain.

The little settlement had among its enemies the Iroquois, the Jesuits, and all the Canadian officials, as Cadillac, unlike them, received his commission directly from the king: and, moreover, this post threatened to divert profitable trade from Montreal and Quebec. He was arrested at Quebec in 1704 upon charges of official misconduct, but, after vexatious delays, was triumphantly acquitted. He returned to Detroit in the fall of 1706, and in 1707 marched against the Miamis and reduced them to terms. Visiting the Illinois country, he reported the discovery of a silver mine, afterward called the La Mothe mine. He next established a post among the Indians of Alabama. He punished the hostile Natchez tribe, who made peace; and a fort was erected in their country in 1714, named Fort Rosalie, in honor of Mme. de Pontchartrain; another was built at Natchitoches, to prevent the Spaniards approaching the French colony. In 1711 he was made governor of Louisiana, then an almost unknown wilderness, but failed in his endeavor to open trade with Mexico. In 1717, after the perfecting of John Law's "Mississippi scheme," the government and trade of Louisiana passed into the hands of his new "western company," and Cadillac returned to France. In 1787 the commonwealth of Massachusetts confirmed to his granddaughter, Mme. Gregoire, so much of Mount Desert Island as was not already granted to others.