The Burnside Rifle Co. manufactured these Spencer Model 1865 carbines circa 1865-1866, serial numbered in the approximate range 1-23000, chambered for use with 56-50 "50 Spencer" rimfire. Many of these Spencer carbines were issued by the U.S. Army in the American West during the Indian Wars, seeing various conflicts with Native American tribes until they were replaced by the Springfield Trapdoor rifles and carbines. Plenty still saw continued use out West until the end of the 19th century. The top of the receiver has the four-line address/patent date and Burnside Rifle Co. marking along with "MODEL/1865". The left of the stock is stamped with a crisp boxed script "ESA" (Erskine S. Allin) inspection cartouche. It has a ladder rear sight graduated to 900 yards, saddle ring mounted on the left of the stock, and is equipped with the Stabler cut-off. Matching serial number "33273" marked on top of the receiver and bottom of the barrel. Most of these Model 1865 Spencer carbines saw hard use out west, with this being an exceptional example that somehow saw minimal use.