Statistics for occurrence #1 of “Port Republic” in page 239 of The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 10: The Armies and the Leaders.:

...d—these are the Pelican Rifles of Baton Rouge, Louisiana, later merged into the Seventh Louisiana Volunteers which suffered the heaviest loss of any Confederate regiment engaged in the fight at Port Republic , June 9, 1862.
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Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
† Port Republic (Virginia, United States) 1,356 2 48 0 0 user votes
Port Republic (Maryland, United States) 0 0 0 0 0 user votes
Port Republic (New Jersey, United States) 0 0 0 0 0 user votes
Port Republic (Ohio, 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.