My husband and I were just visiting Andersonville Civil War Prison Cemetery and POW Museum in Andersonville, Ga. It is now a National Cemetery.They have a computer there which lists the deceased Civil War soldiers buried there. The name is given, plus any known information - such as "3rd PA - Cavalry - Private - etc - and sometimes date of death and cause" - you might contact the Museum there where the computer is located. We were able to finally locate James L.Coleman who was from Indiana County, PA - but they had listed the wrong number for the headstone and the wrong section. We gave them the corrected information and were able to take pictures of the headstone.
if you go to www.google.com and type in Andersonville, GA you will see several sites and one will probably be the National Cemetery and Museum - there will be other info and some phone numbers.
Years ago my husband sent away for the Civil War record of his ancestor - but we had to have some information first - you will need to know the State, the Division or some kind of information like that - "Pennsylvania Volunteers" or something that will help.
Also there are several sites about Civil War dead - you might try Cindy's List on the internet and see what you can find.One of them, as I remember it, will be for divided into two parts - one list for Federals and the other for Confederates.I looked up another ancestor there and found his information as to state etc.I plan to write for that information as he was the grandfather of my husband (had many children and my husband's mother was one of the youngest!)
Maybe someone else is researching the same person and could help you more.Hope you find the records you need and get more information.