This group has a listing of "colored" troops in the Civil War, but the link to that listing is down. At any rate, if your ancestor isn't listed there, you can have him listed.

http://home.usmo.com/~momollus/

There is also a monument in Washington to the black troops in the Civil War where his name should be listed. I think that the "gens de colour" site has a link to it. You can write to them and ask for more information.