Wagon Masters in the Civil War

Question

My Ancestor, John Kerr served in Company D of the 39th Iowa Volunteer Infantry, and was detailed to serve as Wagon Master in 2. M.D., 2nd Division, XVI Corps on 26 Feb 1864 by order of BG Thomas W. Sweeney who commanded the 2nd Division at the time. Later in November-December, 1864, he became the Wagon Master of the 2. M. Dept., 4th Division, XV Corps and served in that position for the remainder of the war. 
 My first question is, what does 2. M. D. stand for? 
 Are there Division or Corp records that have information on the Wagon Masters of these Divisions? 
 On the NARA website, under Wagonmasters Serving the Union During the Civil War, there is a J. Kerr listed, but it has him serving in Washington DC rather than with his Division. This list talks about about civilians serving as Wagon Masters, so I'm not sure if this is my John Kerr or not? 
 Any help would be appreciated! Thank You! 
 Keith Chapman

Textual Reference Branch, Archives II · Answer

KeithChapman 
 Thank you for posting your request on History Hub! 
 We searched the National Archives Catalog and located the series Indexes to the Carded Records of Soldiers Who Served in Volunteer Organizations During the Civil War in the Records of the Adjutant General's Office, 1762 - 1917 (Record Group 94) that includes an index card for John Kerr . The index card indicates that there should be a Compiled Military Service Records (CMSR) for John Kerr in the series Carded Records Showing Military Service of Soldiers Who Fought in Volunteer Organizations During the American Civil War in the Record Group 94. Unfortunately, the records for most [state] Volunteers have not been microfilmed or digitized. To request a copy of his non-digitized service record, please download the NATF Form 86 , fill it out to the best of your knowledge, and mail it to the address on the form or submit your order via eservices.archives.gov . We suggest using online ordering to expedite your request as electronic orders will be received and entered into their system more quickly. Please include a copy of the file unit from the Index. For more information see Requesting Copies of Older (pre-WWI) Military Service Records . 
 We searched the National Archives Catalog and located the series Letters Received, 1863 - 1917 (documenting 1850 - 1917) in the Records of the Adjutant General's Office, 1762 - 1917 (Record Group 94) that includes letters, reports, and papers relating to the military service of officers of the Regular Army, officers of Volunteers in the Staff Corps commissioned by the President, and officers commissioned by brevet appointment in the Regular Army and Volunteer organizations. Portions of these series have been digitized and are available using the Catalog. For more information about the non-digitized records, please email the National Archives in Washington, DC - Textual Reference (RR1R) at archives1reference@nara.gov . 
 We searched the National Archives Catalog and located the series Regimental and Company Books of Civil War Volunteer Union Organizations, 1861 - 1867 in the Records of the Adjutant General's Office, 1762 - 1917 (Record Group 94) that include a file unit titled Regimental and Company Books of the 39th Iowa Infantry Regiment. See also Records Relating to Civil War Units for additional unit records. For more information about the non-digitized records, please email the National Archives in Washington, DC - Textual Reference (RR1R) at archives1reference@nara.gov . Their office will be able to answer specific questions about the records of interest. 
 We hope this is helpful. Best of luck with your family research! 
 Sincerely, 
 Textual Reference Archives II Branch (RR2RR) 
 RR2RR 23-40114-LR