# Brown County, South Dakota Brown County lies in the northeastern reaches of Dakota Territory, a region of open prairie that drew settlers northward in the years before South Dakota achieved statehood in 1889. For the Cooper family, it was the place where they put down roots after leaving the older, more established country of the East. Oscar F. Thaddeus Cooper, born in Ceres, Pennsylvania, and his wife Rosalthea "Rose" Angelia Lanphere, born in New York, had married in 1867 and raised eight children. Sometime before 1884, the family made their way west to Brown County. They were counted here across a span of years — in November of 1884, again in February of 1889 in the months just before statehood, and once more in November of 1891. These were the years of homesteading and settlement, when families like the Coopers worked the prairie soil and built lives on land that had only recently been opened to farming. Brown County was where the Coopers' children grew toward adulthood. Among them was Gladys Aurine Cooper, who would later marry Sven Albert Pearson on June 5, 1912. Sven, too, had made his home in this county, part of the same community of families settling the northeastern Dakota plains. The Coopers did not remain permanently. In time they moved on to Hecla, still within the same corner of the state, and around 1910 Oscar and Rose left South Dakota altogether for Cayuga, North Dakota, where Oscar died in 1911. But for nearly three decades, Brown County was the center of the family's world — the place where they were repeatedly recorded as residents, where their daughter came of age, and where the next generation formed the ties that carried the family forward.