Statistics for occurrence #1 of “Potomac river” in chapter 1.1, section c.1.1.1 of Southern Historical Society Papers, Volume 25.:

...he York, the York and the James, the James and the Nottoway, and the Eastern Shore of the Chesapeake Bay. The whole Atlantic and Bay Coasts from Hatteras to Assateague Island and the mouth of the Potomac river , were accessible to war steamers far above the head of tidewater, and the rivers and estuaries so parted each from the others that they could not readily or adequately support each other in their de...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Potomac River (United States) 286 2 0 0 0 user votes
Potomac River (Maryland, United States) 2 0 0 0 0 user votes
Potomac River (Maryland, United States) 2 0 0 0 0 user votes

† This entity has been selected by the automated classifier as the most likely match in this context. It may or may not be the correct match.