The Battle of the Badlands was fought in Dakota Territory, in what is now western North Dakota, between the United States army led by General Alfred Sully and the Lakota, Yanktonai, and the Dakota Indian tribes. The battle was fought August 7–9, 1864 between what are now Medora and Sentinel Butte, North Dakota. It was an extension of the conflict begun in the Dakota War of 1862. Sully successfully marched through the badlands encountering only moderate resistance from the Sioux.

The Dakota War of 1862, also known as the Sioux Uprising, the Dakota Uprising, the Sioux Outbreak of 1862, the Dakota Conflict, or Little Crow's War, was an armed conflict between the United States and several eastern bands of Dakota collectively known as the Santee Sioux. It began on August 18, 1862, when the Dakota, who were facing starvation and displacement, attacked white settlements at the Lower Sioux Agency along the Minnesota River valley in southwest Minnesota. The war lasted for five weeks and resulted in the deaths of hundreds of settlers and the displacement of thousands more. In the aftermath, the Dakota people were exiled from their homelands, forcibly sent to reservations in the Dakotas and Nebraska, and the State of Minnesota confiscated and sold all their remaining land in the state. The war also ended with the largest mass execution in United States history with the hanging of 38 Dakota men.