What made the Sioux Indians upset during the wounded knee massacre?

The Sioux Indians were upset during the Wounded Knee Massacre primarily due to the U.S. government's broken treaties and the loss of their lands, culture, and way of life. The massacre, which occurred in December 1890, was sparked by tensions over the Ghost Dance movement, which many Sioux believed would restore their ancestral lands and way of life. When U.S. troops attempted to disarm the Sioux at Pine Ridge Reservation, a scuffle broke out, leading to the indiscriminate killing of hundreds of Sioux men, women, and children. This tragic event symbolized the violent suppression of Native American resistance and the culmination of decades of conflict and betrayal.