Mark, the soldier you're looking for is Pvt. John W. Townsend, Co. B, 1st Arkansas Regiment Infantry, although technically he was a discharged veteran at the time of his capture.

He enlisted at Arkadelphia on May 8, 1861, and was mustered into service with his company at Lynchburg, Virginia, on May 19, 1861, for one year. He was discharged on a surgeon's certificate of disability at Camp Price, Aquia Creek, Virginia, on January 27, 1862, and returned to his home in Clark County, Arkansas. When captured on April 2, 1864, he identified himself as a private in Co. B, 1st Arkansas Infantry. He was received at Military Prison, Little Rock, on May 3, 1864; received at Rock Island Barracks, Illinois, on July 21, 1864; and was released on taking the oath of allegiance on October 31, 1864. The remarks section of his oath state that he had volunteered for frontier service in the U.S. Army, but was rejected. He was described as a 21-year-old farmer, born in Polk County, Georgia.

He applied for and received an Arkansas Confederate pension in 1906 (Pension File No. 9381). He died in 1908.