Jolliet

Louis Jolliet (1645–1700) was a French-Canadian explorer, navigator, fur trader, and cartographer best known for his 1673 expedition down the Mississippi River with Jesuit priest Jacques Marquette. The voyage produced the first detailed maps of a large portion of the Mississippi basin and helped establish French claims in the interior of North America.

Jolliet was born in 1645 in the Kingdom of France, likely in the Normandy region. He moved to New France in the 1660s, where he worked as a fur trader and surveyor. In 1673, he joined Marquette on a mission organized by the French authorities to explore the Mississippi River from its upper course and to search for a route to the Gulf of Mexico. The expedition reached the Arkansas River before turning upstream again; the pair documented Indigenous groups, geography, and resources, and left a enduring geographic record of the interior.

Following the Mississippi voyage, Jolliet continued to work in roles related to the fur trade, navigation, and land surveying, contributing to the mapping and economic development of New France. He died circa 1700 in New France; exact details of his death remain uncertain.

Legacy of Jolliet persists in geographic naming and historical scholarship. The 1673 expedition is viewed as a pivotal moment in early North American exploration, facilitating subsequent French efforts in the interior. The surname Jolliet preserves the original French spelling with two Ls, while the city of Joliet, Illinois, bears a name derived from his legacy, though its spelling uses a single L.