Statistics for occurrence #1 of “Potomac” in entry harper-s-ferry of Harper's Encyclopedia of United States History:

...
A town in Jefferson county, W. Va.; 49 miles northwest of Washington; at the junction of the Shenandoah and Potomac rivers; the scene of several stirring events during the Civil War period. Within twenty-four hours after the passage of the ordinance of secession by the Virginia convention, April 17, 1861, the au...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Potomac (Illinois, United States) 2 0 0 0 0 user votes
Potomac (Maryland, United States) 1 0 1 0 0 user votes
Potomac (Montana, United States) 0 0 0 0 0 user votes
Potomac (United States) 0 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.