In 1851, the four Dakota bands signed an agreement with the United States Government ceding their lands west of the Mississippi River in exchange for a reservation along the Minnesota River and annual payments. The Treaty of the Traverse des Sioux, signed July 23, 1851, was an agreement with the Sisseton and Wahpeton Dakota. The Treaty of Mendota, signed August 5, 1851, was an agreement with the Mdewakanton and Wahpekute Dakota. The land ceded was more than 30 million acres and included nearly all of present day southern and western Minnesota, parts of Iowa and parts of South Dakota.
The treaties were negotiated by then Territorial Governor Alexander Ramsey and prominent fur trader and politician Henry Sibley. The acting commissioner was Luke Lea. It was argued by Ramsey and Sibley that the beautiful and lush western lands were being underutilized and were of no use to the Dakota. Settlement in the region was growing, and Ramsey and Sibley were anxious to open the lands to settlers that would plow and till the soil. They further argued that the Dakota would benefit from a much smaller territory where they would be much closer with the other members of their nation. For the Dakota, survival had become difficult as their hunting grounds had become depleted through years and years of the fur trade. The promise of annual payments was attractive to the Dakota, many of whom were starving, as a way to gain the resources they needed to survive.
The Dakota chiefs were reluctant to sell their land, but felt as if they had little choice. If they had not agreed to sell, they might have lost their land and been left with nothing. Unfortunately for the Dakota, the terms of the treaties were rarely met or were unfavorable. Avarice traders often inflated their claims and found ways to obtain the money promised to the Dakota. Reservation life was difficult, denying the Dakota of their traditional culture and ways of living. All these things led to poor conditions and discontent that eventually resulted in the U.S. – Dakota War of 1862.
Williams Watts Folwell, A History of Minnesota, Vol. 1, (St. Paul: The Minnesota Historical Society, 1922).