William,
Samuel H. Evetts was a private in company B, Speight's Batt'n 15th Texas Infantry. Sam was 18 when he mustered in at Millican in Captain M. D. Herring's Company.
I also have a G. H. Evetts private company B, 19 years old. And Hugh Evetts 25 years old Pvt. and Corp. Co B.
More family ???
Yes, the 15th was a Texas Confederate unit that fought west of the Mississippi.
I hope this helps,
Gary D. Bray