Please post pics of the back and any marks!Posting a picture of the back may help in someone identifying it. Neat find and good luck.
This is an Art Nouveau era buckle depicting the story of Mazeppa - Mazeppa is the subject of a poem written by poet Lord Byron in 1819.
Mazeppa (Byron) - Wikipedia, the free encyclopedia
Buffalo Bill did perform the "Mazeppa Ride" as part of his Wild West show, and Mazeppa was a very popular theater production in the mid-late 1800's, your buckle could be American made and sold as a souvenir from such an event.