"The Union" engraved Reed & Barton heavy fork

I found this heavy fork today in a bin of silverware. It is marked "Reed & Barton" followed by a '12' on the back side and engraved "The Union" on the handle . It's approximately 8" long and quite heavy, with a dark patina. Thanks for looking and letting me know if you have information on this piece.

***I will add better photos tomorrow.