not 100% sure,
but it was used for the millitary motto, cavallry officers had it on there swords, an eagle with a banner with E Pluribus Unim written in it you also find it on the officer silver reathed belt plate same again eagle with a banner above with E Pluribus Unim, so it might be a millitary bridal? as i said not 100% sure but its the only thing that springs to mind right now without seeing a pic,
one other thing it could also have a masonic connection to it as this motto was also used by the masons, and going back in history at that time if you were a mason you were proud to show it and it wasnt a kept secret as of nowdays, lots of presidents or high ranking officers or even well known people like buffalo bill were masons, buffalo bill even had a masonic walking stick to show how proud he was, anyway thats another story and theory but a possable conection, Don