Cool postcard !!!
Would have to assume Dayton, OH.
The logo looks like STC. Which could be St. Christopher's. There is a St. Christopher's School in Richmond, VA. But, that school wasn't founded until 1922.
Beating Gettysburg (PA) is your main clue. The key would be a better date. Probably May, but not sure if I see 1912. Maybe try to look up Gettysburg baseball scores in 1912, or years about then. Wouldn't be surprised that you might find something.
The one thing I can tell you player #8 "Hank" probably isn't going to help much .....
