34,000 Burnside Rifle Co. Model 1865 Spencer carbines were manufactured beginning late in the Civil War and first delivered early in the post-war era. Nearly all were used to fulfill U.S. Government contracts. This is one of 19,000 fitted with a Stabler cut-off, and it has the standard markings and features other than the "U.S./COL. TER" on the left side of the butt which indicates it is one of 500 Spencer Carbines transferred by the Ordnance Department to the Colorado Territory on October 16, 1868. Colorado became a state on August 1, 1876. See page 129 of "Spencer Repeating Firearms" by Roy Marcott for a similar example. Spencers were one of the most advanced firearms of the Civil War and continued to see use by the U.S. Army, Native American groups, and settlers in the West in the late 19th century.