The Northwest Indian War (1785–1795), also known as Little Turtle's War and by other names, is a war between the United States and a confederation of numerous American Indian tribes for control of the Northwest Territory.

It follows centuries of conflict over this territory, first among Indian tribes, and then with the added shifting alliances among the tribes and the European powers - France, Great Britain, and their colonials.Under the Treaty of Paris (1783), which ended the American Revolutionary War, Great Britain had ceded to the U.S. "control" of the Northwest Territory, which is occupied by numerous American Indian tribes.

Despite the treaty, the British maintain forts and policies there that support the Indians in the Northwest Territories.

President George Washington directs the United States Army to halt the hostilities between the Indians and settlers and enforce U.S. sovereignty over the territory.

The U. S. Army, consisting of mostly untrained recruits supported by equally untrained militiamen, suffers a series of major defeats, including the Harmar Campaign (1790) and St. Clair's Defeat (1791), which are resounding Indian victories.

About 1,000 soldiers and militiamen are killed and the United States forces suffer many more casualties than their opponents.After the St Clair's disaster, Washington orders General "Mad" Anthony Wayne to organize and train a proper fighting force.

Taking command of the new Legion of the United States late in 1793, Wayne leads his men to a decisive victory at the Battle of Fallen Timbers in 1794, which finally brings the conflict to an end.

The defeated Indian tribes are forced to cede extensive territory, including much of present-day Ohio, in the Treaty of Greenville in 1795.