Dear Mr. Braun,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located 2 series and 47 file units in the Records of the U.S. Forces in Southeast Asia (Record Group 472) that pertain to the 11th Cavalry Regiment. Please note that some of the records have been digitized and may be viewed online using the Catalog. For access to the non-digitized records, please contact the National Archives at College Park - Textual Reference (RDT2) via email at firstname.lastname@example.org.
Please note that 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 RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your research!