Carroll Family Genealogy Forum
Do you know for sure that your Patrick was from Chicago at the time he married and had children? If so, I would suggest that you go to your local FHC and get the microfilmed records of Catholic churches from that area of Chicago during that time. In many cases these are the only records to have survived the Chicago fire in 1871. I have been researching my ancestor, Joseph Carroll who came to Chicago's south side in 1865 from Ireland. It is a good bet that your Patrick was naturalized in the Chicago area. These records are also available at the FHC.
Is funny that I should come across your message. I was just at my FHC looking through records of several Chicago churches and I did find a Partick Carroll in the 1860's records. I thought at the time that he may have been a brother of my Joseph. Another suggestion is to try the Chicago City Directories for that period. They can help you pinpoint an address which will help to find the church your relatives attended.
There is a lot of information out there. Good Luck.