A free Illinois State Archives database of Illinois marriages 1763-1900. Since it is an ongoing project, many counties have records beyond those limits. Updates are availabe at Counties Included in the Illinois Statewide Marriage Index.
This online index, an ongoing project of the Illinois State Archives and the Illinois State Genealogical Society, is a treasure for Illinois researchers. The index covers most counties and dates but not all -- check the list of counties and time periods above. Lee, Marshall, Putnam, and Woodford counties have no listings. A few post-1900 marriages have crept in. Searching is by surname or full name of either bride or groom. You can search either statewide or in a particular county. Names are completed, i.e., if you search for grooms surnamed HAMM the results will include HAMMER and HAMMERSCHMIDT. You can search for as little as two letters of the surname. No searching by given name only. No Soundex. Results include the original license number, if any, and instructions are given for obtaining copies of the original records, which are not available on line.
Copies of some marriage records may be ordered from the Illinois Regional Archives Depository (IRAD) for a minimal copy charge and postage is free.