Statistics for occurrence #1 of “Potomac River” in chapter 4 of Admiral David D. Porter, The Naval History of the Civil War.:

... purpose of strengthening their great lines of defence, the speedy maturing of their plans enabling them to get possession. One of the first ideas of the Confederates was to get possession of the Potomac River , fortify its banks, and thereby cut off all communication between Washington and the sea. Their object was to prevent the transportation of troops from the North to the seat of government by sea, for...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Potomac River (United States) 286 12 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.