A nice example introduced in 1874 in the early part of the Indian Wars of the West.
This cavalry bit was designed by Captain Wm, Shoemaker, and adopted by the Army as the Model 1874 bit. Used all through the Indian Wars, as sturdy, lighter weigh bit. Overall smooth metal finish with some areas of light old rust. Marked “ROCK ISLAND” on right side cheek piece. US bosses in brass on both side.