Red Cloud (pictured), a Native American leader of the Oglala Lakota tribe, signed the Treaty of Fort Laramie, ending Red Cloud's War and establishing the Great Sioux Reservation.

Red Cloud was a leader of the Oglala Lakota from 1865 to 1909. He was one of the most capable Native American opponents whom the United States Army faced in the western territories. He led the Lakota to victory over the United States during Red Cloud's War, establishing the Lakota as the only nation to defeat the United States on American soil. The largest action of the war was the 1866 Fetterman Fight, with 81 US soldiers killed; it was the worst military defeat suffered by the US Army on the Great Plains until the Battle of the Little Bighorn 10 years later.

The Oglala are one of the seven subtribes of the Lakota people who, along with the Dakota, make up the Očhéthi Šakówiŋ. A majority of the Oglala live on the Pine Ridge Indian Reservation in South Dakota, the eighth-largest Native American reservation in the United States.

The Treaty of Fort Laramie is an agreement between the United States and the Oglala, Miniconjou, and Brulé bands of Lakota people, Yanktonai Dakota, and Arapaho Nation, following the failure of the first Fort Laramie treaty, signed in 1851.

Red Cloud's War was an armed conflict between an alliance of the Lakota, Northern Cheyenne, and Northern Arapaho peoples against the United States and the Crow Nation that took place in the Wyoming and Montana territories from 1866 to 1868. The war was fought over control of the western Powder River Country in present-day north-central Wyoming and Montana.

The Great Sioux Reservation was an Indian reservation created by the United States through treaty with the Sioux, principally the Lakota, who dominated the territory before its establishment. In the Fort Laramie Treaty of 1868, the reservation included lands west of the Missouri River in South Dakota and Nebraska, including all of present-day western South Dakota. The treaty also provided rights to roam and hunt in contiguous areas of North Dakota, Montana, Wyoming, and northeast Colorado.