Long home to the Sisseton, Wahpeton, and Cuthead Yanktonaise Sioux, the area became part of Deuel and Cheyenne Counties in 1862, with Deuel extending north to the 46th parallel in 1872. The Reservation, extending south to Lake Kampeska in a giant flatiron, was established in 1867. Grant County included the part southeast of the Reservation from 1873 to 1883, when Roberts County was created and named for S.G. Roberts, Territorial Councilman of Fargo. It was organized on August 6, 1883, by Frederick Dittes, Charles Crissey, Indian Agent, and Reuben R. Hall, and Dittes’ Residence, Travare, two miles southwest of Browns Valley, was named county seat. In 1884 Wilmot won the election but, after losing two court actions, stole the records and was named county seat by the 1885 legislature. It in turn lost an election in 1898 to Sisseton, which, fearing court action, in turn stole the records again to win approval in the 1900 election. White settlement on the Reservation came in 1892 and the railroad reached Sisseton in 1893. Post offices were established at Sisseton Agency in 1872, Wilmot in 1881, White Rock in 1885, Corona in 1886, Summit, Sisseton and Effington in 1892, and Rosholt, Victor, Hammer, and Claire City in 1914, when the Soo Line entered the county.