The first homesteaders arrived in the county in 1866. Ohio natives William O. Bussard and William C. Whitaker filed claims on the West Fork of the Big Blue River in the county's northeastern portion. Settlement of the area was slow until 1870; it was concentrated in the county's northern part, in part because the surveyed route of the Burlington and Missouri River Railroad ran through York County just north of the present-day York-Fillmore county line. In 1870, Fillmore City, the county's first town, was established on the Big Blue about north of present-day Grafton; in 1871, the county's first post office opened in Fillmore City.