Statistics for occurrence #1 of “Boonsboro” in chapter 8.63 of Robert Underwood Johnson, Clarence Clough Buell, Battles and Leaders of the Civil War: Volume 2.:

...derals, which seemed so mysterious to us on that 14th of September. An order of General Lee, made while at Frederick, directing Jackson to capture Harper's Ferry, and Longstreet and myself to go to Boonsboro ‘, had fallen into the hands of the Federals, and had been carried to General McClellan. This order (known at the South as the Lost Dispatch) was addressed to me, but I proved twenty years ago...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Boonsboro (Maryland, United States) 743 42 41 0 0 user votes
Boonsboro (Virginia, United States) 38 0 0 0 0 user votes
Boonsboro (Maryland, United States) 0 0 0 0 0 user votes
Boonsboro (Missouri, 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.