Nice large coat-sized officer's Dragoon button, with beautiful black patina from laying in the Arizona desert for over a century. This came from the collection of an elderly gentleman (now deceased) in Tucson who used to metal detect in southern Arizona.  This was in a box marked "Fort Buchanan."  Fort Buchanan was in use from 1857 to 1861 and was garrisoned by several companies of U.S. Dragoons; Captain Richard S. Ewell was the commanding officer there prior to becoming a Confederate general of Gettysburg infamy.  Thanks for looking!