1637-1675. French Jesuit missionary and explorer. He went to Canada in 1666, explored the upper lakes of the St Lawrence, and in 1673 with Louis Jolliet (1645-1700), set out on a voyage down the Mississippi on which they made the first accurate record of its course. In 1674 he and two companions camped near the site of present-day Chicago, making them the first Europeans to live there.