Dear Mr. Smith,
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 contact the Office of Vital Records for the state in which they resided as well as review the FamilySearch Research wiki for United States Death Records.
We hope this is helpful. Best of luck with your research!