Veterans Badge found

[longf70]

Found this badge in a union camp in January. I sent the picture to American Digger and they done some research for me and it actually made it into this months Just Dug section. I have had several people look at it at recent shows but no one can give me a value for it. It is a Sons of Union Veterans badge and i speculate it was dropped at a revisit to a camp site by a union veteran. Can anyone give me a value. Some people has told me it was issued around 1870.
Thanks