I found this buckle yesterday in northern illinois. I have found other military buttons , marked US , at the same field. There is no writing on it, seems to be made of copper or nickle. As you can see it's not very big. Any ideas?
Thanks
Is the other end broken off or not? If there is a broken end then it almost Looks like a horse buckle cover too prevent the horses tail from getting caught.
Your find is a broken Mosman's 1879 Patent buckle-shield (buckle cover) from horse-harness gear. Yours is an uncommon version, having a "cutout" design on it. Most are solid, like the one in the photo below. Also see the Mosman 1879 Patent diagram. They were mostly civilian usage, but of course the army used them on horsegear too.