For 10 points, name these people whose chiefs have included Sitting Bull and Crazy Horse.
These people's first recorded encounter with Europeans was with the French traders Radisson and Groseillers in 1659. Three hundred of the Santee branch of these people were sentenced to die for attacks on settlers, but Abraham Lincoln commuted the death sentence of most of the men. A prominent chief of these people, Red Cloud, fought in a namesake war against US forces in both Montana and Wyoming. These people were massacred by the US 7th Cavalry at Wounded Knee Creek. For 10 points, name these people whose chiefs have included Sitting Bull and Crazy Horse. 
These people's first recorded encounter with Europeans was with the French traders Radisson and Groseillers in 1659.
Sioux [prompt on Oglala, Yankton, and Lakota]