Hi Elizabeth-

I was just looking into this yesterday.

You can get the information you are looking for at:
Cook County Recorder of Deeds
118 N. Clark
Room 120
Chicago, IL 60602
(312) 603-5050
(This is in downtown Chicago)

Unfortunately, they don't do anything by mail or phone so you are going to have to do your own look-up in person or hire a researcher to do it for you.

Good Luck in your search
Paul