Who was the founder of Detroit? July 5, 2020 by Pamela Landy Antoine de la Mothe Cadillac, a French explorer and administrator, founded Fort Pontchartrain du Detroit in 1701. The Cadillac automobile is named for him. Related Answers Where are the following forts located? Where was Fort William Henry? Was Pittsburgh named after someone named Pitt and what did he have to do with Pennsylvania? Who was the “Hair Buyer of Detroit”? What does “Detroit” mean?