Jolliet or Joliet, Louis(both: jō`lēĕt', jō'lēĕt`, Fr. lwē zhôlyā`), 1645–1700, French explorer, joint discoverer with Jacques MarquetteMarquette, Jacques
, 1637–75, French missionary and explorer in North America, a Jesuit priest. He was sent to New France in 1666 and studied Native American languages under a missionary at Trois Rivières.
..... Click the link for more information. of the upper Mississippi River, b. Quebec prov., Canada. After a year's study of hydrography in France and some years as a trader and trapper on the Great Lakes, Jolliet was appointed (1672) as leader of an expedition in search of the Mississippi. He and Father Marquette, with five voyageurs, set out from St. Ignace in May, 1673, went to Green Bay, ascended the Fox River, portaged (at the site of Portage, Wis.) to the Wisconsin River, and descended to the Mississippi. The group followed the west bank south until they passed the mouth of the Arkansas River; then, having convinced themselves that the river emptied into the Gulf of Mexico, they ascended its eastern bank. They came to the Illinois River, ascended it, and, on the site of modern Chicago, portaged to the Chicago River, and again reached Lake Michigan. Marquette remained in the West while Jolliet went east to make his report, but in the Lachine Rapids, near Montreal, Jolliet's canoe overturned and his records were lost. His brief narrative, written from memory, is in essential agreement with Marquette's, the chief source account of the journey. Jolliet was rewarded with the gift of Anticosti Island in the Gulf of St. Lawrence, which was, however, seized by the British while Jolliet was absent on explorations in Labrador and around Hudson Bay. In 1697 he was made royal professor of hydrography and given a small seigniory near Quebec.
See biographies by J. Delanglez (1948) and V. L. S. Eifert (1961); M. S. Scanlon, Trails of the French Explorers (1956).