Early Connecticut settlers established the Congregational church as the tax-supported state church until 1818 when the state constitution was accepted abolishing the connection between church and state. Sometimes, if one parish was getting too large, a second was formed that became a precursor to a new town with the permission of the general assembly. Other denominations followed eventually, particularly the Baptists and Episcopalians from Rhode Island on the eastern border with Connecticut. Information in Connecticut's church records has often been found to be more informative, complete, or accurate than the town vital records.
Many town churches have deposited their older records for safe keeping with the Connecticut State Library. A List of Church Records in the Connecticut State Library is available at the cost of a photocopy, which updates the library holdings.
Approximately one-quarter of those records housed at the Connecticut State Library has been indexed in a format similar to that of the Barbour and Hale collections with individual index slips and bound compilations of individual churches. This Church Record Index File is state-wide, goes beyond 1850, but does not include all church records. Even in a town with more than one Congregational church, generally only the first is included in this index. Notably, many church records in incorporated cities have not been indexed.
Many town churches have deposited their older records for safe keeping with the Connecticut State Library.
In addition to vital records, indications of migration in listings of past and future church membership are often found when dates of admission or dismissal are given in membership lists for churches.