Statistics for occurrence #1 of “St. Louis” in page 179 of Benson J. Lossing, Pictorial Field Book of the Civil War. Volume 2.:

...lum, an eminent engineer officer, as his chief of staff, and Brigadier-General Schuyler Hamilton as assistant chief. Both officers had been on the staff of General Scott. The Headquarters were at St. Louis . General Hunter, whom Halleck superseded, was assigned to the command of the Department of Kansas. General Don Carlos Buell had superseded General Sherman, and was appointed commander of the Depar...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
St. Louis (Missouri, United States) 2,551 131 591 1 0 user votes
St. Louis (Michigan, United States) 4 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.