Manufactured circa 1855-56 with an estimated total quantity of only about 1,020. The lock is marked "SPRING / FIELD / 1855" vertically behind the hammer and has the eagle motif over "US" ahead of the hammer. The barrel tang is dated "1855" and the left rear of the barrel has the "V / P / eagle head" proofs. All parts were finished bright. Iron blade front sight and three folding leaf rear sight. Two piece trigger guard with a large round sling swivel mounted on the rear, button head steel ramrod affixed to the muzzle by a large oval, U-shaped iron swivel and mounted with a 3/4 length straight grip walnut stock secured by a single barrel band, with a brass forend cap and steel buttplate marked "US" on the tang. The left stock flat has a boxed "JS" cartouche. This is the only Model 1855 U.S. Martial arms made for manual priming, lacking the Maynard tape priming system.