William S. Newton (1823-1882) served the Union primarily as an assistant surgeon with the 91st Ohio Volunteer Infantry, but also spent a few months as acting surgeon with the 2nd Virginia Cavalry (US). Toward the end of the war, he was promoted to surgeon for the 193rd Ohio Volunteer Infantry. Newton’s units fought in the Appalachian Highlands, mostly in Virginia and West Virginia. He treated wounded soldiers after significant battles including Opequon and Cedar Creek. In May 1864, following the Battle of Cloyd’s Mountain, John Hunt Morgan’s Raiders captured Newton and other medical personnel. After three weeks, Newton and his fellow prisoners were given the option of either treating Confederate soldiers or going to Libby Prison; they chose the latter. Newton spent only three days at Libby Prison before being released, but the experience took a significant toll on his health.The letters in this volume, addressed mostly to Newton’s wife, Frances, provide a window into fighting in the Appalachian borderlands, where the differences between battle, guerilla warfare, and occupation were often blurred. As a noncombatant, the doctor observed life beyond troop movements and the brutality of war. Newton’s detailed letters cover his living quarters, race relations, transportation and communication, the comfort of a good meal, and the antics of his teenage son Ned. This book provides new insights into the medical and social history of the war, the war in Western Virginia, local and regional history, the perspective of a noncombatant, life on the home front, and the porous lines between home and battlefront.