In due time, Burton said, the route was extended to Point Isabel (now Burnside), a main riverboat town on the Cumberland River. A short time later the route was extended to Monticello.
After the Somerset Post Office opened, other horseback routes were established to Crab Orchard, Mt. Vernon, London, Whitley County Courthouse (now Williamsburg), Marsh Creek (now in McCreary County) and Jamestown.
Burton said mail service was expanded and improved during these years, but between 1803 and 1875 mail transportation was exclusively by horseback, horse-drawn carriages or wagons.
A revolution in mail service came in 1875 when Southern Railway System extended its line through Somerset from Cincinnati to Chattanooga, Burton said.
John Tohill was postmaster when the existing post office building was dedicated in 1968.