This is an outstanding example of a U.S. Contract Colt Model 1851 "Army/Navy" revolver that was manufactured in 1856. This Colt Model 1851 Navy revolver features the small rounded brass trigger guard and beveled loading slot. The barrel and cylinder have the Colt military blue finish and the loading lever, frame and hammer are color casehardened. The revolver has a one-piece oiled walnut grip. The lower right side of the grip is stamped with the script initials of the Ordnance final inspector "RHWK" (Capt. Robert Henry Kirkwood Whitely) in an oval. The lower left side of the grip is stamped with the three script initials of the Ordnance sub-inspector in a rectangle with rounded ends. The cylinder is roll-engraved with the Texas Navy battle scene, "ENGAGED 16 MAY 1843" and "COLT'S PATENT No." The top of the barrel is roll-stamped "-ADDRESS SAML COLT NEW-YORK CITY-" in one line. "COLTS/PATENT/U.S." is stamped on the left side of the frame in three lines. Small "H" Ordnance sub-inspection marks are stamped on the left grip heel, top of the back strap, bottom of the trigger guard bow, cylinder and top barrel flat. The full serial number is stamped on the bottom of the barrel lug, frame, trigger guard, back strap and cylinder. The loading lever is stamped with the partial serial number "1879". All of the visible serial numbers match. The first Colt Model 1851 "Army/Navy" revolvers were issued to the newly formed 1st and 2nd Cavalry regiments in 1858-1859 and subsequently saw hard service on the frontier and in the early part of the Civil War. Other "Army/Navy" revolvers were issued to federal volunteer cavalry regiments at the start of the Civil War. U.S. martial "Army/Navy" revolvers are rarely found with any finish whatsoever.