In the years 1914 and 1915 there were three major leagues in baseball. The third one was the Federal League, and the Chicago team played in what is now known as Wrigley Field. In fact, the ballpark was built for them.
I found this interesting article today about the Federal League, and a movie that was recently discovered featuring a scene at a Federal League game. You can read it here.
For geeks only (and I say that with love).