Statistics for occurrence #1 of “St. Louis” in chapter 8.22 of Robert Underwood Johnson, Clarence Clough Buell, Battles and Leaders of the Civil War: The Opening Battles. Volume 1.:

...8th of August. All except the regulars had been enrolled since the attack on Sumter in April, and but little time had been possible for drill and instruction. They had been moved and marched from St. Louis and points in Kansas, taking part in several spirited but minor engagements, and were ill-provided with clothing and food, but their spirits were undaunted, and they were devoted to their leader....
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
St. Louis (Missouri, United States) 2,551 128 591 0 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.