Marriage and divorce records, along with birth and death records, are known as vital records, and are maintained by government agencies. Historical marriage and divorce records are generally kept by state archives and sometimes by city archives as well. Recent marriage and divorce records are generally kept by courts or by a Department of Vital Records. The bottom line is, there is no single source for accessing such records, so searching them out can be a challenge.
Compile your information. Start by consolidating what you know. Write down the name of the people who married or divorced, including a maiden name, if known. Also write down any details of the event, such as where it took place and the date it occurred.
Find the right resource. Use the link provided in the References section to find the state or city agency that is likely to have the records you are seeking. Most jurisdictions have websites you can visit for details on obtaining records, but some do not, and will require a phone call or written communication.
Check historical records. If the marriage or divorce record you are looking for predates the records available in vital record offices, then look in sources of archived records. Many state archives keep marriage and divorce records and an increasing number of states have digitised their records and made them available online.
Check ancestry.com, a subscription genealogy service with a large collection of archived records, including millions of historical marriage and divorce records.