110th Regiment, Ohio Infantry
The 110th Regiment was organized at Camp Piqua, Ohio, October 3, 1862. It went to Washington, D. C., May 24-June 2 and mustered out June 25, 1865.
The Wikipedia article for the 110th Regiment gives additional history.
Larry Stevens' site gives references to sources about the 110th Ohio Infantry as well as brief historical information.
Companies in this Regiment with County of Origin
Men often enlisted in a company recruited in the counties where they lived though not always. After many battles, companies might be combined because so many men were killed or wounded. However if you are unsure which company your ancestor was in, try the company recruited in his county first.