In my stuff back in NY is a B/W portrait photo of a Union Soldier.
His name was Captain Charles S. Marsh. (Yes, the name is not a coincidence, he's my great-great-great-grandfather).

He served as a Captain in a Ohio Artillery Unit. (My family are all Buckeyes originally).

And that's about all I know about him. I don't now in which unit, in which army, (I am going to guess Army of the Potomac as thats where alot of Ohio Units were) and have no idea in which campaigns he might have fought in or what happened to him.

(Rumor has it: he had children, but that is a unsubstantiated rumor )

Does anyone know where I might be able to find out more information? Perhaps a muster list or something?

Thanks.

Have you tried Ancestry.com yet?

This is a decent site...

http://www.civilwarindex.com/

I found a Charles J Marsh on there, from an Ohio Artillary regiment, but not a Charles S Marsh

Here is the soldier search, it doesn't give much, but may help

http://www.itd.nps.gov/cwss/soldiers.cfm

IF you ever find out what Unit he was with, the National Archives should have copies of his service records, sometimes takes a couple shots before they dig them up.

Here's another resource, this one will take sifting through

http://civilwarroster.com/cw/cw-oh.html

I checked the artillery pages, no records contain Marsh, still worth looking at