The first anniversary game of the Baltic Base Ball Club will be played on Monday, May 1st. All friends and lovers of the game are respectfully invited to attend, near the terminus of the Fifth street railroad.
-St. Louis Daily Press, April 30, 1865
The Baltic Club was mentioned by E.H. Tobias as one of the clubs that took part in a torchlight parade in 1865, welcoming back the Empire Club after they returned victorious from their trip to Freeport, Illinois. The significance of this notice in the Daily Press, however, is in the fact that if the Baltics were celebrating their first anniversary in May of 1865 then the club was founded in the spring of 1864.
Again, as I mentioned a few days ago when talking about the Laclede Club in 1861, the source material, up to this point, was unanimous in stating that the Empires were the only baseball club active during the war years. But if the Baltic Club was founded in the spring of 1864 then it is most probable that they were playing baseball that year. What's the point of forming a baseball club if you're not going to play baseball?
While I haven't, as of yet, found the records of any club other than the Empires playing baseball during the 1861-1864 era, I think it's only a matter of time. At this point, I have little doubt that there were clubs besides the Empires active in St. Louis during the Civil War.