Thanks to Joe Di Cola for sending the following information:
"The Lefaucheux revolver (a pin-fire revolver, manufactured in Belgium) was one of the only foreign-manufactured revolver imported by the U.S. government during the Civil War, primarily for the cavalry. A few were said to have been used in the Confederate armies."
Here are a couple images of Joe's Lefaucheux revolver from the Civil War:
Very interesting! Thanks for posting!