Dear Mr. Nelson,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located the series Court Martial Case Files, 12/1800 - 10/1894 in the Records of the Office of the Judge Advocate General (Army) (Record Group 153) but were unable to locate a file pertaining to Colonel Isaac G. Wilson. For more information about these files, please contact the National Archives at Washington, DC - Textual Reference (RDT1) at email@example.com.
We also located Letters Received, 1805 - 1889 in the Records of the Adjutant General's Office, 1762 - 1917 (Record Group 94) that includes a file for 1861 - Wilson, Isaac T - File No. W1281. This file is digitized and may be viewed using the Catalog.
For information about Federal courts in Chicago and Illinois in the 1860s, please contact the National Archives at Chicago (RM-CH) 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 RDT1 and RM-CH. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful.