This Regiment was organized at Camp Jackson, Ohio, from April 18 to 25, 1861. It was composed of two companies from Mount Vernon, two from Delaware, two from Kenton, two from Marion, one from Canton and one from Wooster. On the second day of May the Regiment moved to Camp Dennison, and on the fourth day of May was mustered into the United States service. Immediately came the President’s call for 300,000 troops for three years, when a majority of the Regiment signified their intention to enter the three years’ service. The Regiment was mustered out at Columbus, Ohio, by reason of expiration of term of service from the 18th to the 24th day of August, 1861. This Regiment was organized at Camp Dennison, Ohio, in June, 1861, to serve three years. The original members (except veterans) were mustered out June 21, 1864, by reason of expiration of term of service, and the veterans and recruits, together with the veterans and recruits of the Eighth Regiment Ohio Volunteer Infantry, were consolidated and designated the Fourth Battalion Ohio Infantry.