Father Jacques Marquette (1637-1675) was a French Jesuit missionary who founded Michigan’s first European settlement, Sault Ste. Marie, and later founded St. Ignace, Michigan. In 1673 Father Marquette and Louis Jolliet were the first Europeans to explore and map the northern portion of the Mississippi River.
-Wikipedia

Reuben Gold Thwaites was a noted historian and a director of the Wisconsin Historical Society. He carried out extensive research on Father Marquette as well as other French Jesuits in North America, compiling a 71-volume collection of Jesuit documents called The Jesuit Relations and Allied Documents.