Dear Mr. Waits,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located a series titled Record Books of Executive, Legislative, and Judicial Offices of the Confederate Government in the War Department Collection of Confederate Records (Record Group 109) that contain Roster of Officers, 1861-1865. For access to these records, please contact the National Archives at Washington, DC - Textual Reference (RDT1) via email at email@example.com. We were unable to locate records of the 16th Arkansas or the 58th Arkansas.
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 suggest that you contact the Arkansas State Archives for records of the units that served during the Civil War.
We hope this is helpful. Best of luck with your research!