I have verified through Texas pension for Civil War soldiers that my gg father, Needham Alexander Boon, was in the 19th Texas Regiment, Infantry. Copies of his pension request show said unit. He was found by me as N A Boon on the Johnson Co, TX. pension list.
I have not be able to find any other records such as company muster reports. I don't know if he was with the unit at any of the battles and at all battles. Illness killed many of their number. He was in from 1862 to 1865 and died in 1917.