Sunlit Field by Lucy Kennedy 1950
 

I finally read The Sunlit Field, a novel by Lucy Kennedy from 1950. Often described as the first adult baseball novel written by a woman, it contains many interesting baseball references and descriptions from 1857. A preface states the only character based upon a real person is the one based upon Walt Whitman, but the teams are real, and there are other characters who seem to based upon real players. The development of public rules is central to the story and there is a character who pitches a curve ball.
If you are interested in a fairly interesting novel that involves the very early days of organized team baseball in. Brooklyn and New York, you might enjoy this one.