The Fort Dearborn massacre occurred on August 15, 1812, near Fort Dearborn, Illinois Territory (in what is now Chicago, Illinois) during the War of 1812. The massacre followed the evacuation of the fort as ordered by the U.S. General William Hull. This event is also sometimes known as the Battle of Fort Dearborn.
Fort Dearborn's commander Captain Nathan Heald ordered all whiskey and gunpowder to be destroyed so it would not be seized by the local Indian tribes allied with the British, although he had agreed to these terms a few hours earlier. He then prepared to abandon his post. Heald remained at Fort Dearborn until support arrived from Fort Wayne, Indiana, led by his wife's uncle, Captain William Wells. A column of 148 soldiers, women and children then left Fort Dearborn intending to march to Fort Wayne. However, about one and a half miles (2 km) south of Fort Dearborn, at about what is now 18th Street and Prairie Avenue, a band of Potawatomi warriors ambushed the garrison, killing more than fifty and capturing the remainder as prisoners to sell to the British as slaves. The British purchased the captives and released them immediately afterwards.
Fort Dearborn was burned to the ground, and the region remained empty of U.S. citizens until after the war had ended.
Survivors' accounts differed on the role of the Miami warriors. Some said they fought for the Americans, while others said they did not fight at all. Regardless, William Henry Harrison claimed the Miami fought against the Americans, and used the Fort Dearborn massacre as a pretext to attack the Miami villages. Miami chief Pacanne and his nephew, Jean Baptiste Richardville, accordingly ended their neutrality in the War of 1812 and allied with the British.