I grabbing some items from 1904 American Horse Breeder issues.
Provides some results for Chicago area tracks of 1904.http://www.mi-harness.net/eur/ChicagoRsts1904.pdf
Two of these, I'm without any previous references to:
1) Austin Park (not sure if there was a city at that time or just the park that exists today?), near Cicero Blvd & I-290.
2) Pullman (on very south side; not sure that's correct terminology) near Lake Calumet.
Anybody know these areas or aware of any references to tracks in these locations?