John W was my third great grandfather. Given his age, and living in Frederick Co, one would think that he rendered service during the civil war.
Has anyone been able to find any evidence?
Yes... John W Boyd was a Sgt. He served with Company A of the 23rd Regiment of Virginia Cavalry.
I'll upload the service records to his profile and throw the Find A Grave reference on there for you...
I added what I could - I've sent a request to collaborate with the owner of the profile so I can finish it up...