Dear Ms. Gemmell,
Thank you for posting your request on History Hub!
The Federal Government does not ordinarily create or maintain birth, death, marriage or divorce records. Such records are made and kept by State and local governments rather than the National Archives. We suggest that you search for records of your parent’s marriage in the Historical Records Collection “United States Marriages” and review the FamilySearch research wiki for United States Marriage Records. We also suggest that you search local newspaper archives for mention of your parent’s marriage. Please check for access at your local library as many library systems subscribe to these sites, making them free for their patrons.
We hope this is helpful. Best of luck with your family research!