From Ohio History Central
French explorer and soldier Antoine Laumet de la Mothe Cadillac originally built Fort Detroit in 1701, naming it Fort Pontchartrain. The French hoped to use the fort to build alliances with the Indians living in the Ohio valley in order to protect their interests in the region from British encroachment. The fort was built along the Detroit River at the gateway between Lake Erie and the western Great Lakes. It consisted of a small town surrounded by a stockade wall. Fort Detroit soon became a center of the fur trade between the French and local Indians.
The French surrendered the fort to the British in 1760 as a result of the French and Indian War. At this point the British named it Fort Detroit. The British reinforced the defenses around Detroit, making it even stronger. Indians attacked Fort Detroit during Pontiac's Rebellion in 1763, but they were not able to overcome its strong fortifications in spite of a five-month siege.