Thanks for the reply. In fact, I had some success since I posted this message. As you suggested, I found a local researcher who was willing to go directly to the Cook County archives and conduct a search for me. She found the divorce file that I had hoped for (it was from 1928), and in fact it was far more detailed and revealing than I could have imagined. Some 50 pages of proceedings in total. There were even some personal letters in there that formed part of the evidence in the case. It was quite a discovery.