Morning Reports will be your best route to find out when he joined his actual unit prior to his death.
Dear Mr. Shaw,
Thank you for posting your request on History Hub!
If you have not done so already, we suggest that you request a copy of your great uncle’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 man]y 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.
The information you seek may also be contained in your great uncle’s Individual Deceased Personnel File (IDPF). IDPFs from 1940-1976 for U.S. Army personnel with surnames that begin with A-L are in the custody of the National Archives at St. Louis (RL-SL). For more information about these records, please contact RL-SL via email at email@example.com.
As Mr. Schneider noted, morning reports may also be a helpful source of information for you. Morning reports for Army units from November 1, 1912 to 1959 are in the custody of the National Archives at St. Louis (RL-SL). For more information about these records, please contact RL-SL.
In addition, we searched National Archives Catalog and located the series World War II Operations Reports, 1940-1948 in the Records of the Adjutant General's Office (Record Group 407) that may contain records related to your great uncle’s unit. The series Unit Histories, 1943-1967 in the Records of U.S. Army Operational, Tactical, and Support Organizations (World War II and Thereafter) ( Record Group 338) 3 files related to the 10th Infantry Regiment in the 1940s that may be of interest to you. While these records generally do not contain information about individuals, they may be able to provide some context for the activities of your great uncle’s unit during the time of his service. These records have not been digitized. Please contact the National Archives at College Park - Textual Reference (RDT2) at firstname.lastname@example.org for further assistance with these records.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RL-SL and RDT2. Also, NPRC will continue servicing requests ONLY associated with medical treatments, burials, and homeless veterans seeking admittance to a homeless shelter. 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!