Statistics for occurrence #1 of “Piedras Negras” in chapter 3 of Philip Henry Sheridan, Personal Memoirs of P. H. Sheridan, General, United States Army .:

...he First Regiment of United States Infantry, then stationed in Texas. The company to which I was attached was quartered at Fort Duncan, a military post on the Rio Grande opposite the little town of Piedras Negras , on the boundary line between the United States and the Republic of Mexico. After the usual leave of three months following graduation from the Military Academy I was assigned to temporary duty ...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Piedras Negras (Coahuila, Mexico) 25 10 1 0 0 user votes
Piedras Negras (Guatemala) 0 0 0 0 0 user votes
Piedras Negras (Guatemala) 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.