Statistics for occurrence #1 of “Washington” in chapter 1 of The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 4: The Cavalry:

...ppropriate superior arms and equipment. The regiment in this photograph is the Thirteenth New York Cavalry at Prospect Hill, Virginia. They are no longer raw troopers but have become the eyes of Washington and its chief protection against the swift-riding Mosby and his men. The troopers were drilled on foot as well as mounted. month prior to this march; and in the issue we drew everything on the list...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Washington (United States) 21,192 93 3,586 1 0 user votes
Washington (Washington, United States) 232 0 0 0 0 user votes
Washington (Virginia, United States) 224 0 4 0 0 user votes
Washington (Alabama, United States) 88 0 0 0 0 user votes
Washington (West Virginia, United States) 14 0 2 0 0 user votes
Washington (Georgia, United States) 6 0 6 0 0 user votes
Washington (Idaho, United States) 4 0 4 0 0 user votes
Washington (California, United States) 2 0 0 0 0 user votes
Washington (Missouri, United States) 2 0 2 0 0 user votes
Washington (Louisiana, United States) 1 1 1 1 0 user votes
Washington (Arkansas, United States) 0 0 0 0 0 user votes
Washington (Kansas, United States) 0 0 0 0 0 user votes
Washington (Maine, United States) 0 0 0 0 0 user votes
Washington (Michigan, United States) 0 0 0 0 0 user votes
Washington (Minnesota, United States) 0 0 0 0 0 user votes
Washington (Mississippi, United States) 0 0 0 0 0 user votes
Washington (Missouri, United States) 0 0 0 0 0 user votes
Washington (Nebraska, United States) 0 0 0 0 0 user votes
Washington (Nevada, United States) 0 0 0 0 0 user votes
Washington (New Jersey, United States) 0 0 0 0 0 user votes
Washington (New Mexico, United States) 0 0 0 0 0 user votes
Washington (New Mexico, United States) 0 0 0 0 0 user votes
Washington (Ohio, United States) 0 0 0 0 0 user votes
Washington (Ohio, United States) 0 0 0 0 0 user votes
Washington (Ohio, United States) 0 0 0 0 0 user votes
Washington (Oklahoma, United States) 0 0 0 0 0 user votes
Washington (Texas, United States) 0 0 0 0 0 user votes
Washington (United Kingdom) 0 0 0 0 0 user votes
Washington (Utah, United States) 0 0 0 0 0 user votes
Washington (Vermont, 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.