Marriage Index: Illinois, 1851-1900 Please enable JavaScript in your browser to complete this form.Please enable JavaScript in your browser to complete this form.Your Email *EmailConfirm EmailFull Name You Want Searched *Helpful InformationSubmit This valuable index provides data on around 707,000 people who got married in Illinois from 1851 to 1900. It’s an excellent source of information as it compiles marriage records from fifty-eight Illinois counties that were previously uncollected.