If your ever in Waco, Texas check out the Texas Ranger Museum. There are exhibits on the Civil War and many books in the gift shop on Texas, Texans and the Texas Rangers during the Civil War. Lots of guns.
One book that caught my eye that I will consider for the future is "Civil War and Revolution on the Rio Grande Frontier", a photographic history. Wow! What photographs, many unpublished before of Union and Confederate soldiers in and from Texas. Extremely clear and unusual photos of people and their cloths in the mid-eighteen hundreds.