In early July 1927, the Ohio Department of Highways implemented the system of United States Numbered Highways that had been approved by the states in late 1926.Lima News, Many Highways Take National Number System, June 5, 1927Lima News, New System of Markers to be Used in State, July 3, 1927: "work of attaching the plates bearing the highway numerals will be completed by July 9" This resulted in the renumbering of many of the state highways to avoid overlaps with the new U.S. Routes and numbers used by both classes of route. In addition to the U.S. Routes, a new State Route 6 was formed, extending West Virginia Route 6 northwest from the Ohio River at Bridgeport to Norwalk. (Route 6 later became U.S. Route 250 in both states.)
