Swift F. Mullin enlisted in Co. K, 2nd Arkansas Infantry, U.S. Volunteers, at Clarksville, Arkansas, on January 24, 1864, and was mustered into service on February 19, 1864, for three years. He died of "fever" at Clarksville, Arkansas, on April 11, 1864.

William F. Mullin enlisted and was mustered into service at the same time as Swift. He served with this command to the end of the war, and was mustered out of service with the regiment on August 8, 1865.