In July 1864, several members of the Kelly-Larimer wagon train were killed by a large party of Oglala Sioux. The graves of five victims—7-year-old Mary Kelly and four men—are located near present Glenrock, Wyo. Fanny Kelly, held captive by the Sioux, later wrote a book about her trials.
In 1850, the U.S. Congress authorized a conference to persuade Plains Indian tribes to live and hunt within newly designated, separate territories, and to accept payment for the damage caused by emigrants crossing their lands. The conference in September 1851 drew 10,000 Indians to the confluence of Horse Creek and the North Platte River, 30 miles east of Fort Laramie. The treaty that was signed there, the Horse Creek Treaty of 1851, permanently changed the terms of Indian-white relations on the northern Great Plains.
