Statistics for occurrence #1 of “Potomac river” in chapter 1.18 of Southern Historical Society Papers, Volume 23.:

...y was already known to be assembling on the Potomac, in Loudoun, so that General Stuart's march ordered by General Longstreet would take the cavalry east of the Bull Run mountains and bring it to the Potomac river , below where the enemy's army was being concentrated. Of course this might readily prove to be inconsistent with the chief aim of the movement ordered by General Lee, which was that General Stuart ...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Potomac River (United States) 286 0 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.