Dear Mr. Keller,
Thank you for posting your request on History Hub!
We searched the Access to Archival Databases (AAD) and located the Records of World War II Prisoners of War, 12/7/1941 - 11/19/1946 in the Records of the Office of the Provost Marshal General (Record Group 389) that includes one file for an individual named Hamilton, John D. We also located the World War II Army Enlistment Records database that includes files related to 20 individuals named Hamilton, John D. If you are able to identify any of these individuals as your grandfather, you may be able to use the information in the file when requesting a copy of his Official Military Personnel File (OMPF).
If you have not done so already, we suggest that you request a copy of your grandfather’s Official Military Personnel File (OMPF). OMPFs and individual medical reports for enlisted men of the U.S. Army who were separated from the service after October 1912 and before 1959 are in the custody of NARA's National Personnel Records Center (NPRC) in St. Louis. In many cases where personnel records were destroyed in the 1973 fire, proof of service can be provided from other records such as morning reports, payrolls, and military orders, and a certificate of military service will be issued. Please complete a GSA Standard Form 180 and mail it to NARA's National Personnel Records Center, (Military Personnel Records), 1 Archives Drive, St. Louis, MO 63138-1002. Veterans and their next of kin also may use eVetRecs to request records. See eVetRecs Help for instructions. For more information see Official Military Personnel Files (OMPF), Archival Records Requests.
Due to the COVID-19 pandemic, NPRC will continue servicing requests ONLY associated with medical treatments, burials, homeless veterans seeking admittance to a homeless shelter, and those involving the VA Home Loan program. If your request is urgent, please see Emergency Requests and Deadlines. Please refrain from submitting non-emergency requests such as replacement medals, administrative corrections, or records research until NPRC returns to pre-COVID staffing levels. Please check archives.gov/veterans for updates to the NPRC operating hours and status. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this information is helpful, and best of luck with your family research!