Statistics for occurrence #1 of “Harper's Ferry” in year 1861, month June, day 17 of Rebellion Record: a Diary of American Events, Diary from December 17, 1860 - April 30, 1864:

... is the standard gray, furnished by the State--the muskets the Springfield rifle. General Patterson crossed the Potomac at Williamsport, and marched down the Virginia banks of the Potomac towards Harper's Ferry .--National Intelligencer, June 18.
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Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Harper's Ferry (West Virginia, United States) 10,974 139 304 19 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.