Need help with unknown "US" insignia

[Sarbaz]

I little collect US collar disc. Such disñ to me never met and in book I its too did not see.
I think that this bracket on anything. Can memorable gift, souvenir.

[milmuseum]

I agree with Steve on the date being later. I'm going closer to early WWII or between the wars because it is hollow / stamped.

Thanks
Burt

[SteveR]

I apologize for the photos. They are from "Lords Civil War Collectors encylopedia" Volume 2
I just returned to this thread.
I still maintain that it is a civil war period bridal. They came with and without bridal rossettes.
The fact it has been mentioned that the piece is hollow just tells me that the person speaking does not know anything about mid 19th century horse equipment or insignia.
Late century bridals had a different design insignia.