The following year, he returned to Concord Church to teach, thereafter attended the University of Mississippi from 1855 until his graduation in 1858.
[6] Arnold then returned to teaching at Concord Church until the beginning of the American Civil War, when he enlisted in the Confederate States Army.
[6] Arnold "served as a private in the Columbus Riflemen, Company K, Fourteenth Mississippi Regiment, throughout the war, except during the period of his imprisonment at Camp Douglas, Chicago, after the fall of Fort Donelson".
[5] Arnold was the circuit judge of the first judicial district for a number of years, and according to one source, "bore the reputation of being one of the best the State ever had".
After Orline's death, Arnold married her sister, Florence Lowry, with whom he had two daughters and three sons, one of whom died in infancy.