On November 4, 1791, a multitribal confederation, formed to resist colonial expansion into their historical homelands, routs a large contingent of U.S. troops along the Wabash River in western Ohio.

This one-sided clash, known as the Battle of the Wabash or St. Clair’s Defeat, would be the biggest victory ever won by Native Americans over the United States—with far more casualties inflicted than even the Battle of the Little Bighorn—and would prompt a major overhaul of the American military.

With the passage of the Northwest Ordinance in 1787, the newly independent United States opened an early phase of westward expansion into lands occupied by the Shawnee, Miami, Delaware, Wyandot and other Great Lakes tribes.

Banding together to fight the incursion, the tribes rebuffed an assault in 1790 near present-day Fort Wayne, Indiana, killing 183 U.S. soldiers in the campaign. This prompted the United States to muster an even larger force the following year.

Led by Major General Arthur St. Clair, governor of the Northwest Territory and a veteran of the Revolutionary War, U.S. troops marched north from present-day Cincinnati in September 1791, with instructions to establish a series of military posts and to strike their opponents “with great severity.” Beset with problems from the outset, they advanced only a single mile on the first day. Inexperienced, lacking in supplies, and facing increasingly wet and icy weather, dozens of men deserted and others were discharged.

Even so, St. Clair remained confident, saying that “savages, if violently attacked, will always break and give way—and when once broke, for the want of discipline, will never rally.” Suffering from debilitating gout, St. Clair had purportedly been warned by President George Washington to “beware of surprise.” Yet on November 3, as his force camped along the Wabash River, he posted few watchmen and constructed no field fortifications.

The following morning, he and his 1,400 men were attacked by a roughly equal number of Native Americans led by Miami Chief Little Turtle and Shawnee Chief Blue Jacket. (A young Tecumseh also played a small role in the battle, serving as a scout.) Deployed in a well-organized crescent formation, the Native Americans fired away while, in the words of one observer, moving virtually unseen from tree to tree.

State militiamen fled in panic, throwing the whole U.S. force into disarray, whereas the Army regulars who stood their ground were encircled and mowed down in droves. In just three hours of fighting, at least 600 U.S. soldiers were killed, along with dozens of camp followers. Estimates of Native American deaths range as low as a couple dozen.

However, the Native American victory was short-lived. In 1794, a better-trained, more professional army under the command of General “Mad” Anthony Wayne returned and defeated the multi-tribal confederation at the Battle of Fallen Timbers. By the terms of a subsequent treaty, the tribes were forced to cede most of present-day Ohio, along with portions of neighboring states.