Manufactured during the Civil War by the Massachusetts Arms Co., American Machine Works, and American Arms Co. Thomas Poultney and D. B. Trimble of Baltimore served as Smith's agents. The vast majority of the carbines were issued to several Union cavalry units and have saddle rings on the left side of the action. Interestingly, this American Machine Works example only has "B" on the left barrel flat and right stock flat and an "HJ" stamp on the left stock flat instead of the usual inspection markings and inspector's cartouche. It otherwise has the standard markings and features.

Very good with 70% of the original blue finish fading to a plum brown, 70% of the bright original blue finish on the trigger guard, half of the original blue on the latch, 50% of the original case colors visible on the frame, and dark gray and brown patina on the balance. There are patches of light oxidation and scattered small marks. The wood is also very good and has several nicks and scratches, four notches cut to the right of the buttplate tang, and smooth original finish. The carbine is mechanically excellent and has crisp markings.