Dear Mr. Rambo,
Thank you for posting your request on History Hub!
For a list of units in the Army of Missouri (Confederate States of America), please see Battlefield Atlas of Price’s Missouri Expedition of 1864, written by Charles D. Collins, Jr. and published by the Combat Studies Institute, US Army Combined Arms Center. The information you seek is in Appendix A, pages 193-196.
If you are trying to identify your ancestor’s unit affiliation, there may be a listing for him and his unit in the National Park Service’s Civil War Soldiers and Sailors System.
We searched the National Archives Catalog and located Record Books of Executive, Legislative, and Judicial Offices of the Confederate Government in the War Department Collection of Confederate Records (Record Group 109) which may contain records of some of these units. Please contact the National Archives in Washington, DC - Textual Reference (RDT1) via email at firstname.lastname@example.org to access these records.
We also located Carded Records Showing Service of Military Units in Confederate Organizations in Record Group 109 which may have a record of him. To order copies of these records, please fill out a NATF Form 86 and mail it to Archival Operations Washington D.C., Form 86 – Military, National Archives and Records Administration, 700 Pennsylvania Avenue NW, Washington, DC 20408-0001. You can also place your order online using eservices.archives.gov. For more information, please see Requesting Copies of Older (pre-WWI) Military Service Records. You may also email RDT1 for questions about these records.
Please keep in mind that due to the circumstances of the American Civil War, records for Confederate individuals and organizations did not always end up in federal custody.
We hope this information is helpful. Best of luck with your family research!