Hello Jennifer, thank you for submitting your question to History Hub!
A search in the National Archives Catalog for Record Group 168, Records of the National Guard Bureau, produced nearly 50 results. A couple records series of interest are Annual Returns, 1908 - 1908 and Correspondence and Other Records, 1908 - 1908, which may include
references to your Great Uncle.
For more information about these records, please contact the National Archives at College Park - Textual Reference (RDT2) via email at email@example.com.
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.
The National Guard Association of the United States may also be a good resource.
We hope this is helpful, and thank you again for submitting your question to History Hub.