The path was a network of trails that had long been used by indigenous peoples in pre-colonial America. Nemacolin's Path starts near present-day Cumberland, Maryland, continuing on to Brownsville, Pennsylvania to the neighborhood known today as Redstone located at mouth of Redstone Creek. In colonial America, the site was known as Redstone Old Fort for its defensive installation.
During 1749 and 1750, the Delaware Indian chief Nemacolin and Maryland frontiersman Thomas Cresap supervised improving the trail for the Ohio Company, at the behest of Christopher Gist. They developed the template trail and in large part the route for what became known on the eastern slopes as the eastern part of Braddock's Road. In 1755, the eastern part of Nemacolin's Path was used as military route by British General Edward Braddock in his attempt to capture Fort Duquesne.
Crossing the Allegheny divide was a major task, requiring much planning, time and effort, until well into the 19th century. East-west highways were not built across the border between Virginia and West Virginia until late in the century. The two regions were separated by some of the harshest terrain in the mountain chain. Except for using the Cumberland Gap, travelers would have to go hundreds of miles to the north or south to get through the mountains, as the ridgelines are oriented north-south and are nearly impassable.
Nemacolin's Trail was later improved as the Cumberland Road, the National Road, the National Pike, and eventually U.S. Route 40, or the National Highway. U.S. Route 40 became one of the first officially recognized highways in the United States. The earlier road, known as the Cumberland Road/National Road, ran on the first cast iron bridge constructed in the United States, at Dunlap's Creek. Nemacolin's Trail became the gateway by which settlers in Conestoga wagons or stage coaches reached the lands west of the Appalachian mountains.