1890
Wounded Knee Massacre
The setting
Wounded Knee Creek, Pine Ridge Reservation, South Dakota
Open creek bottom where Spotted Elk's (Big Foot's) band was encamped and surrounded
Read the historical account
A massacre, not a battle. While troops disarmed the band, a shot was fired and the cavalry opened fire with rifles and Hotchkiss cannon, killing roughly 250-300 Lakota, most of them unarmed women, children, and elders.
This entry is labeled honestly as a massacre. It was not a contest of tactics: a surrounded, largely disarmed group was killed by overwhelming firepower.
What followed
Widely regarded as the symbolic end of the armed Indian Wars and one of the worst atrocities against Native peoples in U.S. history. It is intentionally excluded from the tactical factors analysis because framing it as a 'victory' would misrepresent what occurred.