13th Infantry Regiment was organized during the fall of 1861 and included Bates' Texas Infantry Battalion. The unit contained artillery, cavalry, and infantry companies and was reorganized several times. Attached to the Trans-Mississippi Department, it served in Texas guarding the coast between Galveston and Matagorda. In April, 1864, the regiment contained 18 officers and 334 men, and in April, 1865, there were 392 present for duty. It was included in the surrender in June. The field officers were Colonel Joseph Bates; Lieutenant Colonels Reuben R. Brown and Henry P. Cayce; and Majors Robert L. Foard, Stephen S. Perry, and Lee C. Rountree.