Hey Jonsie, Welcome to the forum !
The buckle is not a military issue, most likely a civilian decorative buckle. It could be cw period though, I don't know for sure, maybe somebody else could help you there. Keep digging and find a bullet and hopefully more will follow.
Look at my buckle I posted under this topic. I know it is not military issue, but trying to find the time period for artifacts helps you know if your looking in the right spots !! Good Luck.
Bryan
