Marriage Certificates

Except in Cook County, all Illinois marriage certificates since 1877 have a Board of Health form attached that asks for the town of birth, the full names of the parents, and if this is a first marriage.

Research tip: The 1900 and 1910 censuses asked how many years a couple had been married. While not always perfectly accurate, this should get you into the right range of years to search when you're looking through the indexes.