Parkhurst enlisted and was commissioned at age 37 in the 9th Michigan Infantry as a Lt. Col. on Sept. 10, 1861 at Coldwater (Mich.). He was captured at Murfreesboro (Tenn.) on July 13, 1862 and exchanged Dec. 3, 1862. He served as Provost Marshal, 14th Army Corps, Oct. 1863-Sept. 1865 and Provost Marshal, General Miltary District Tennessee, June 25-Nov. 10, 1865. He was discharged at Detroit (Mich.) on Nov. 10, 1865. For gallantry and meritorious service he was named Brevet Brig. Gen., U.S. Volunteers on May 22, 1865. After the war he lived in Coldwater (Mich.). He was appointed Marshall for the Eastern District of Michigan in 1866. (For further information see the 9th Michigan Infantry regimental history and Parkhurst's book, "Recollections of Stone's River", describing his Civil War experiences.).