Traverse de Sioux – All land east of the Big Sioux, which included the areas of Brookings County, much of western Minnesota and eastern Iowa, was signed over to the United States government by the upper bands of the Dakota nation.
1856
Sioux Falls is established.
May 1857
The first two settlements in Brookings County, Flandreau (named for Judge Charles E. Flandreau) and Medary (named for Governor Samuel Medary of the Minnesota Territory) were established.
April 1858
A new treaty was signed after Traverse de Sioux proved ineffective.