We know there was a colonial road, but I had never heard of this one. The colonial road crossed the Potomac at modern day Wilson Bridge and headed in a NE direction through that portion of Prince Georges County.
This one, well, it’s hard to know the route, because the map is so old. I’m putting the photo up here so I can see it better. At first glance, it looks like it crossed the Potomac west of Georgetown.
Wiki has an entry on the Great Trail, but nothing on the portion in our area.
Searching google, I found this reference:
The Great Trail has been known by other names such as the Virginia Path, Potomac Road, and Warriors Path. This trail was a war path for the Iroquois into the Carolinas and was used by warriors in their expeditions against the Cherokee and Catawba. The course of the Warrior Path through the Cumberland Valley may explain why there were so few American Indian villages in Cumberland County prior to the Shawnee occupation in 1698. The Susquehannocks, who previously controlled the region, were an enemy of the Iroquois, and it is unlikely they would establish settlements near an Iroquois warpath.16
One of the major paths through Cumberland County was the Great Trail. It crossed the Susquehanna River at Paxtang (Harrisburg) and went to Letort’s Spring (Carlisle), Mt. Rock, Big Spring, and Shippensburg. After leaving the County it continued south through Chambersburg, across the Potomac River, and eventually into Virginia and the Carolinas. Present-day U.S. Route 11 generally follows the old path.