Scott,

Here is a little info. for you from the book Compendium of the Confederate Armies Texas

Texas 4th Field Artillery Battery
Nickname: Van Dorn Light Artllery

Organized on July 1, 1861. Surrendered at Arkansas Post, Arkansas on Jan. 11th 1863. It was armed with four guns on April 1, 1864. Designated as the 4th Field Artillery Battery on Nov. 19th 1864. It was armed with two 12-lb. Howitzers and two 12-lb. Napoleons in May 1865.
Surrendered by General E. K. Smith, commanding Trans-Mississippi Department, on May 26th 1865.

First Commander: Captain William T. Mechling
Captain Horace Haldeman

Battles:

Arkansas Post - January 4-11, 1863
Red River Campaign - March-May 1864
Camden Expedition - March-May 1864
Mansfield - April 8, 1864
Pleasant Hill - April 9, 1864

I hope this helps you,
Gary D. Bray