F. V. DeCoster came in the spring of 1858 and he started working in carpentering, teaching, and in the fur trade. He stayed in the fur business most of the time until the Indian Uprising of 1862 broke out. He already had become friendly with Chief Little Crow, the head of the massacre movement, and also with Chief Shakopee, buying fur and venison from them at various times. In 1859–1860, DeCoster left Kingston for a trip through the south for quite a while, but he returned to Kingston. When the Civil War started, DeCoster enlisted and fought in many battles, even personally capturing some Confederate soldiers. After the close of the war, he remained in St. Louis for four months and then he returned to Kingston and engaged in the general mercantile trade. This he conducted until 1868 when he sold out and became a partner in a flouring mill. He remained in that until the spring of 1871, when he moved to Litchfield. Most of his time in Kingston, he was a justice of the peace.