Fort Dearborn  Fort Dearborn was a United States fort built in 1803 beside the Chicago River, in what is now Chicago, Illinois. It was constructed by troops under Captain John Whistler and named in honor of Henry Dearborn, then United States Secretary of War. The original fort was destroyed following the Battle of Fort Dearborn during the War of 1812, and a second fort was reconstructed on the same site in 1816. By 1837, the fort had been de-commissioned. Parts of the fort were lost to both the widening of the Chicago River in 1855, and a fire in 1857. The last vestiges of Fort Dearborn were destroyed in the Great Chicago Fire of 1871. The site of the fort is now a Chicago Landmark, located in the Michigan–Wacker Historic District. The history of human activity in the Chicago area prior to the arrival of European explorers is mostly unknown. In 1673, an expedition headed by Louis Jolliet and Jacques Marquette was the first recorded to have crossed the Chicago Portage and traveled along the Chicago River. Marquette returned in 1674, and camped for a few days near the mouth of the river; then moved on to the portage, where he camped through the winter of 1674–75. Joliet and Marquette did not report any Native Americans living near the Chicago River area at that time, although archaeologists have discovered numerous Indian village sites dating to that time elsewhere in the Chicago region. Two of de La Salle's men built a stockade at the portage in the winter of 1682/1683. In 1682, René Robert Cavelier, Sieur de La Salle had claimed a large territory (including the Chicago area), for France. In 1763, following the French and Indian War, the French ceded this area to Great Britain, and it became a region of the Province of Quebec. Great Britain later ceded the area to the United States (at the end of the American Revolutionary War), although the Northwest Territory remained under "de facto" British control until about 1796. Following the Northwest Indian War of 1785–1795, the Treaty of Greenville was signed at Fort Greenville (now Greenville, Ohio), on August 3, 1795. As part of the terms of this treaty, a coalition of Native Americans and Frontiers men, known as the Western Confederacy, turned over to the United States large parts of modern-day Ohio, Michigan, Indiana, Wisconsin, and Illinois.