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Jeff S...there is no one single resource. But, if you were trying to find out that information, one guy at a time, the logical places to look would be the Spalding or Reach guides for the years you suspect they were in pro ball.
There are also several books of league-specific stats, particularly on higher-level leagues (PCL, AAA), that would give you stats and players.
And...I hate to keep acting like a SABR spokesperson, but there is a SABR member, Ray Nemec, who collates minor lg stats, and I believe that he will send the complete minor lg & major lg stat record of any player on request for $1. I would imagine he is not completely done, so I don't know how far into all of the early c20 and c19 stats he is.