 In 1837, the Mercersburg, Greencastle, and Waynesboro Turnpike was completed, connecting Mercersburg and Waynesboro via Greencastle.This turnpike served as part of a route between Pittsburgh and Baltimore.When routes were legislated in Pennsylvania in 1911, present-day PA 16 was designated as Legislative Route 224 between McConnellsburg and Waynesboro and as part of Legislative Route 44 between Waynesboro and Carroll Valley.