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.:

...ne the location of works, had necessarily to be prudent in their movements, and accurate observations were impossible. The first forts located were Fort Runyon, at the land end of the approach to Long Bridge , about a half a mile from the Virginia end of the bridge proper, and Fort Corcoran, covering the approach to the aqueduct. These footholds were secured by a crossing in force on the night of the 23...
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.