Statistics for occurrence #1 of “Long Bridge” in chapter 6 of The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 5: Forts and Artillery.:

...Several of the officers peer over the parapet, watching for the approach of danger. The first forts located in the defenses south of the Potomac were Fort Runyon, at the land end of the approach of Long Bridge , and Fort Corcoran, covering the approach to the aqueduct. On the night of May 23, 1861, three columns of Federal soldiers crossed the Potomac, one by the aqueduct, one by Long Bridge, and one by w...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Long Bridge (Pennsylvania, United States) 258 22 2 0 0 user votes
Long Bridge (Louisiana, United States) 12 0 0 0 0 user votes
Long Bridge (New York, United States) 10 0 0 0 0 user votes
Long Bridge (Louisiana, United States) 0 0 0 0 0 user votes
Long Bridge (New Jersey, 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.