Others may already be familiar with this site, but I Googled Chicago Catholic churches map yesterday and, among others, came up with http://www.yourmapper.com/list/165/1/catholic-churches/all-catholic-churches -in-the-chicago-archdiocese.htm It has some nice features. For example, you can type in your ancestor's address and see the nearest churches, or click on a church and see others in the area. Unfortunately, it's just existing parishes, but you could always print out a map and draw in the old parish churches. Someday maybe we'll have an online map that shows all the parishes, past and present. Diane