The efforts of Thomas Fitzpatrick, U.S. Indian agent for the upper Arkansas and Platte River since 1846, to negotiate with the Northern Cheyenne, the Arapaho and other tribes lead to a great council at Fort Laramie in 1851.
Treaties are negotiated by a commission consisting of Fitzpatrick and David Dawson Mitchell, U.S. Superintendent of Indian Affairs, with the tribes of the northern plains.