The Battle of Fort Dearborn (sometimes called the Fort Dearborn Massacre) was an engagement between United States troops and Potawatomi Native Americans that occurred on August 15, 1812, near Fort Dearborn in what is now Chicago, Illinois (at that time, wilderness in the Illinois Territory). The battle, which occurred during the War of 1812, followed the evacuation of the fort as ordered by the commander of the United States Army of the Northwest, William Hull. The battle lasted about 15 minutes and resulted in a complete victory for the Native Americans. After the battle, Fort Dearborn was burned down. Some of the soldiers and settlers who had been taken captive were later ransomed. Following the battle, the federal government became convinced that all Indians had to be removed from the territory and the vicinity of any settlements, as settlers continued to migrate to the area. The fort was rebuilt in 1816. Background Fort Dearborn was constructed by United States troops under the command of Captain John Whistler in 1803. It was located on the south bank of the main stem of the Chicago River in what is now the Loop community area of downtown Chicago. At the time, the area was seen as wilderness; in the view of later commander, Heald, "so remote from the civilized part of the world." The fort was named in honor of Henry Dearborn, then United States Secretary of War. It had been commissioned following the Northwest Indian War of 1785–1795, and the signing of the Treaty of Greenville at Fort Greenville (now Greenville, Ohio), on August 3, 1795. As part of the terms of this treaty, a coalition of Native Americans and frontiersmen, known as the Western Confederacy, turned over to the United States large parts of modern-day Ohio, and various other parcels of land including centered at the mouth of the Chicago River. The British Empire had ceded the Northwest Territory—comprising the modern day states of Ohio, Indiana, Illinois, Michigan, Wisconsin, and parts of Minnesota—to the United States in the Treaty of Paris in 1783. The area had been the subject of dispute between the Native American nations and the United States, however, since the passage of the Northwest Ordinance in 1787. The Indian Nations followed Tenskwatawa, the Shawnee prophet and the brother of Tecumseh. Tenskwatawa had a vision of purifying his society by expelling the "children of the Evil Spirit", the American