Here are three letters from John A. McIntosh, who was with the 78th OVI for most of the war. He enlisted on 27 Dec 1861 as a private at age 22. He was promoted to corporal on 15 Jun 1864 and to Sergeant on 1 May 1865. He was mustered out with the regiment on 11 Jul 1865 in Louisville, Ky. He served for the duration of his service in Company I.
Virginia K. Charlton, the great-grandaughter of Catherine (Cate) McIntosh, the older sister of the McIntosh brothers, has also contributed an information sheet that contains additional information on the brothers and their letters