In 1861, Col. Joseph Bates raised the 13th Texas Infantry Regiment in Galveston and Brazoria County with headquarters in Valasco, Texas. The regiment was assigned coastal duty between Galveston and Matagorda most of the war. From May to September 1863, the regiment was moved to Louisiana and served under Gen. Richard Taylor with headquarters in Bashgear City.
I could not find the details of the 13th Texas Infantry in the NPSCWSSS.