Statistics for occurrence #1 of “Mexico” in chapter 8 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.:

...sion of the old Springfield muskets, the best in the world of their kind, into rifled breech-loaders, the new type which the experience of war had brought into being. France had sent an army into Mexico . The United States declared this a violation of the Monroe Doctrine, and the issue was doubtful. The Ordnance Department expected further trouble, but was fully prepared for it. The able officers...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Mexico (Mexico, Mexico) 8,518 0 0 0 0 user votes
Mexico (Mexico) 1,918 0 0 0 0 user votes
Mexico (New York, United States) 45 0 1 0 0 user votes
Mexico (Indiana, United States) 8 0 0 0 0 user votes
Mexico (Kentucky, United States) 0 0 0 0 0 user votes
Mexico (Maine, United States) 0 0 0 0 0 user votes
Mexico (Maryland, United States) 0 0 0 0 0 user votes
Mexico (Ohio, United States) 0 0 0 0 0 user votes
Mexico (Ohio, United States) 0 0 0 0 0 user votes
Mexico (Pennsylvania, United States) 0 0 0 0 0 user votes
Mexico (Pennsylvania, United States) 0 0 0 0 0 user votes
Mexico (South Carolina, 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.