Bryan you found a man William Davis born about 1828 in Tennessee and joined the service at Fayetteville, Ark.
This looks like a very close match. My William Davis was born in 1826 in Tennessee. If I can connect my William to McMinn County, Tennessee. I will wait for the 3rd Great grand Daughter to reply back to me. and I will reply back here and let you know.
Thank you very much.
Mike from Arkansas.