Hi Angie, Illinois state marriage index would not list a marriage in chicago prior to 1871 or thereabouts because of the chicago fire which destroyed most of the records. Have you contacted st. john's church to see if they have any record on your ancestors which would show what church they came from? Also there is an excellent source book on doing resource in cook county which lists churches by demonination and start date.Plus lots of other alternatives to public records. "Chicago and Cook County Sources author Loretto Dennis Szucs. Might be able to get it through amazon on the web or in a library. MOST of the church records in cook county have been microfilmed by the LDS(mormons) Have you contacted any libraries in the indiana location to find out what churches of the same demonination as st. john's(beecher)were there and then located those records? Kathy