He couldn't have participated in the Civil War since it was over in 1865.
You have to look up each relative individually. Most males 1863-1865 were in the Civil War. However you have to look each one up separately.
In the future be sure to post your query, in the location where you think you'll find the answer. That way a local person hopefully will be able to provide the answer or tell you where to look for it. Successful Searching!