Drew, I'm not sure about the History Commission, but our Central Ark. Library main branch houses the Butler Center for Arkansas Studies. In the Civil War collection they have a letter from Van Manning, written at Camp Mason, Va. in Dec of 1861. Also the followind:
Diary: Jefferson Alvis Fowler, 3rd Confederate Infantry Regiment

April 29 to November 29, 1864

Typescript and Edited Copy

Donated by Joseph M. Taylor

Here is the website for the center.
http://www.butlercenter.org/