Jim,
Texas 4th Artillery Battalion (Shea's) organized on Dec. 10th 1861 with two companies. Daniel D. Shea (Captian, Major), commanding with Captain John A. Vernon commanding Company A, and Captain Joseph M. Reuss commanding Company B.
The 4th was in action on October 31-November 1, 1862 at Lavaca Texas.
The 4th was assigned to the 8th Texas Infantry in Feb. 1863. The 8th was commanded by Colonel, Alfred M. Hobby.
The next action for this group was Saint Joseph's Island May 3rd 1863.
Here is how your GGrandfather is listed in the Soldiers and Sailors System.
Jacob Hamm (First_Last)
Regiment Name 4 Battalion Texas Artillery
Side Confederate
Company B
Soldier's Rank_In Private
Soldier's Rank_Out Private
Alternate Name
Notes
Film Number M227 roll 15
Jim, I can't find your uncle in the 4th or the 8th but I do find only one Lewis Hamm in Texas service, here it is.
Lewis Hamm (First_Last)
Regiment Name 25 Texas Cavalry
Side Confederate
Company D
Soldier's Rank_In Private
Soldier's Rank_Out Private
Alternate Name
Notes
Film Number M227 roll 15
CONFEDERATE TEXAS TROOPS
25th Regiment, Texas Cavalry (3rd Texas Lancers) (Gillespie's)
25th Cavalry Regiment [also called 3rd Texas Lancers] was organized by C.C. Gillespie early in 1862. The unit was soon dismounted and ordered to Arkansas. Here it was captured in January, 1863, at Arkansas Post. After the exchange the regiment was consolidated with the 17th, 18th, and 24th Texas Cavalry Regiments (dismounted) and was placed in Deshler's, J.A. Smith's, and Granbury's Brigade, Army of Tennessee. This command fought with the army from Chickamauga to Atlanta, moved with Hood to Tennessee, and saw action in North Carolina. The 25th was organized with about 900 men and had 552 in action at Arkansas Post. At Chickamauga the 17th/18th/24th/25th suffered 200 casualties and in December, 1863, totalled 690 men and 520 arms. Only a remnant surrendered on April 26, 1865. The field officers were Colonel Clayton C. Gillespie, Lieutenant Colonel William M. Neyland, and Majors Joseph N. Dark and Edward B. Pickett.
Note, Some of the men of the 25th did not get captured at Arkansas Post and went on to fight in Polignac's Texas Brigade in Louisana.
Do you have the compiled service records for your soldiers or is this family history you are working with?
It may be that Lewis was captured at Arkansas Post and then went on to join a union outfit but you really need his records to see what happened.
You can order the records at this site if you wish.
http://history-sites.com/research/index.html
I hope this has helped you in some way,
Gary D. Bray