In 1673 Louis Jolliet and Father Jacques Marquette explored the Illinois Country for France. By the 1763 treaty ending the French and Indian War, this area passed to England. During the American Revolution, George Rogers Clark's men captured it for the Commonwealth of Virginia. Illinois was later governed as part of the Northwest Territory, the Indiana Territory, and the Illinois Territory. In 1818, Illinois entered the Union as the twenty-first state. The Northwest Ordinance had placed Illinois' northern boundary at the southern tip of Lake Michigan, but during debate on the statehood bill, Illinois Territory delegate to Congress Nathanial Pope proposed an amendment setting the boundary at its present location. Through Pope's foresight, Illinois gained the fourteen northern counties, including the rich Galena lead mine district and the port of Chicago. The Great Lakes trade route brought settlers from the northeastern states. Nearby towns also claimed distinction: Elgin as the site of a noted watch factory, and Dundee as the home of Allan Pinkerton, who founded a detective agency in 1850 and later served as Abraham Lincoln's bodyguard and as director of the spy service during the Civil War. The Fox River area, once a hunting ground for Potawatomi Indians, became a land of dairy farms, resorts, and sport.