The Barbour Collection consists of births, marriages, and deaths recorded at the town level in Connecticut up through approximately 1850. In the 1910s and 1920s, Lucius Barnes Barbour (Connecticut Examiner of Public Records, 1911–1934) and his team of researchers transcribed the records held at the town level. Those transcriptions were returned to the Connecticut State Library, which transcribed the records onto slips and then into bound volumes by town. Thus, there are two parts of the Barbour Collection: the slip index, and bound volumes for individual towns.
A summary of how the Barbour collection was compiled and how to use it can be found on the AmericanAncestors.org website.
Statewide Slip Index/Abstract
Each slip contains the information found in the original birth, marriage or death record, as well as a citation to the original. They are arranged alphabetically then chronologically in drawers at the Connecticut State Library. They were also filmed by the Family History Library. Film numbers can be found here
Bound volumes were prepared for each town from the slips, containing the same information. Records are combined under one spelling per surname rather than preserving the original as on the slips. Because they represent a transcription of the slips themselves, there is the possibility of errors introduced that do not appear on the slips. Bound volumes were not prepared for the towns of Bolton, Coventry, Enfield, Mansfield, New Haven, Norwich, and Vernon since published compilations of vital records had previously been prepared for these towns. However, these towns are included in the statewide slip index.
Town volumes were also (re)published by Genealogical Publishing in 1994-2002, and can be purchased online.
Many of the records have been transcribed and put online for free access.
As indicated in the repository list above, Ancestry.com has put most (but not all) of the towns together into statewide databases for births, marriages, and deaths.
AmericanAncestors.org has put a collection of all the records together in one database. (They also maintain a list of other Connecticut town resources here.)
The following list shows the volume numbers and town sections as published by the Genealogical Publishing Company with links to free online transcriptions if known. Additions welcome.