If you check with the Confederate Research Center at Hill County Jr College in Hillsboro, Texas, you will find a lot of info. The staff there are very helpful. As you enter the museum there is a sketch type picture published in northern newspapers during the war of a skirmish on Padre Island where one of the Union Soldiers was awarded the Congressional Medal of Honor. I think the Tx cavalry regiment involved was commanded by Col. Buchel, but could be wrong as I am reciting from memory. Six or eight CSA cavalry regiments moved up and down the Texas coast from the Matagorda area to Galveston trying to anticipate and prevent Union landings and raids along the coast during 1863 and early 1864. The Union troops usually stayed close to the coast under the protection of the big guns of their navy gunboats. The north end of Matagoda near the mouth of the Caney was another hot spot during this period. Most of the Union forces were removed and sent to participate in the Red River Campaign in Louisiana in early 1864 as were six of the CSA regiments. A small union force remained at Brazos Santiago at the mouth of the Rio Grande River to slow down the cotton trade via Mexico.