Statistics for occurrence #1 of “Loudon” in part 1.2, chapter 1.5, page 60 of The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 2: Two Years of Grim War.:

...e crossed the Potomac by means of a ford near Williamsport and on the 13th he reached Bolivar Heights. Harper's Ferry lies in a deep basin formed by Maryland Heights on the north bank of the Potomac, Loudon Heights on the south bank, and Bolivar Heights on the west. The Shenandoah River breaks through the pass between Loudon and Bolivar Heights and the village lies between the two at the apex formed b...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Loudon (New Hampshire, United States) 2 0 2 0 0 user votes
Loudon (Tennessee, United States) 2 0 0 0 0 user votes
Loudon (Louisiana, United States) 0 0 0 0 0 user votes
Loudon (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.