Dear Mr. Stull,
Thank you for posting your request on History Hub!
The semi-annual rosters (i.e., April and October) for 1960-74 for Army units are attached to the morning reports of the respective units. All rosters for the period are not available and usually list only enlisted personnel. Paper copies may be obtained from microfilm by writing to NARA's National Personnel Records Center, (Military Personnel Records), 1 Archives Drive, St. Louis, MO 63138-1002. Research and reproduction fees are charged for this service. Please use the enclosed GSA Standard Form 180 to request this information. Or you may use the form on their web site at http://www.archives.gov/veterans/military-service-records/standard-form-180.html.
In addition, we searched the National Archives Catalog and located one series titled Engineer Unit Records, ca. 1965 - ca. 1973 in the Records of the U.S. Forces in Southeast Asia (Record Group 472) that include records of the 815th Engineer Battalion during 1968 (Boxes 916 & 918-924). We also located the Operational Reports - Lessons Learned (ORLL), 1965 - 1972 in Record Group 472 that include 3 file units of the 815th for 1968. For access to and/or copies of these records, please contact the National Archives at College Park - Textual Reference (RDT2) via email at firstname.lastname@example.org.
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 the National Personnel Records Center and RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this information is helpful! Best of luck with your research.