Dear Lee Feldman,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located the file Consolidated Military Officer's File of Benjamin Henry Grierson, Alabama, 1865 in the series Letters Received, 1863-1917 in the Records of the Adjutant General’s Office (Record Group 94) that contains the file code G-553-CB-1865 that you included in your inquiry. These records are also known as “Commission Branch (CB) Files,” and they are arranged chronologically by year, thereunder alphabetically by initial letter of surname of writer, and thereunder numerically. This file has been digitized and can be viewed online via the Catalog. You may contact the National Archives at Washington, DC - Textual Reference (RDT1) at firstname.lastname@example.org for additional assistance with these records.
Next, we located 6 series in Record Group 94 that are related to the War Department’s Appointment, Commission, and Personal Branch (ACP) that may be of interest to you. Arrangement statements for each of these series are listed in the Catalog. Most of these records have not been digitized. For access to and information about them, please contact RDT1.
Plus, we located the series Letters Received, 1861-1889 in Record Group 94 that was created by the War Department’s Volunteer Service (VS) Division. The files are arranged in two sections. The period 1861-1870 is arranged chronologically by year, thereunder by initial letter in the surname of the writer, and thereunder numerically. The period 1871-1889 is arranged chronologically by year and thereunder numerically. These records have not been digitized. You may contact RDT1 with any questions you might have about them.
You may explore other offices under the War Department's Adjutant General's Office in the 1860s in the Catalog. You may also wish to use the Advanced Search feature of the Catalog to search for additional abbreviations or acronyms within Record Group (RG) 94.
Finally, you may also find additional abbreviations and acronyms online at the National Archives’ Guide to Federal Records: Records of the AGO, 1780s-1917.
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. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this information is helpful. Best of luck with your research!
Thanks so much Rachel. This information was very helpful. I am a citizen archivist and currently working on transcribing the Grierson file you referenced. It’s more 1100 pages and I’m only on #220 But now I have a better understanding of the reference numbers attached to the documents.
Thanks again for the detailed response!