The other day I realized that four of the five libraries in my vicinity are on different catalog systems. Elmhurst is in the SWAN network. Glen Ellyn and Villa Park are in the LINC network. Wheaton and Lombard look to be completely independent. Weird.
The way to search all public libraries in one search engine is to use WorldCat. I am an Elmhurst Public Library cardholder, so I have access to WorldCat through the EPL website and with my card number. Hopefully if you’re in Illinois, your library allows you access to WorldCat to search all Illinois libraries. It rocks.