Wes,
I did a little looking earlier when I was reviewing some of the postings and besides the David Terry bio in Texas History Online, the only thing I found was this short unit history.
Terry's Regiment, Texas Cavalry
Terry's Cavalry Regiment was assembled in Montgomery County, Texas, during the spring of 1864. Attached to the Trans-Mississippi, the unit was ordered to Calcasieu Pass, Louisiana, then was active in numerous conflicts in Arkansas. Later it moved to Texas and was placed on commissary duty and disbanded in the spring of 1865. Its commanders were Colonel David S. Terry, Lieutenant Colonel S. H. Brooks, Major J. M. Evans.
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I'd like to know more about these gentlemen, too. I live about a mile from the Montgomery County, TX line.
Jim Martin