The Model 1819 Hall was the first military breech loading firearm issued in large numbers and also the first firearm manufactured with totally interchangeable parts. It took Hall some five years to get the proper tools and machinery assembled to produce the rifles, but in 1826, a government commission disassembled 100 Hall rifles, mixed up the parts, and re-assembled them on newly received stocks with no reported problems and thus confirmed Hall's success. The Hall rifles were first used in combat by the Sixth U.S. Infantry during the Bad Axe Massacre that ended the Black Hawk War in 1832, and Hall rifles and carbines remained in use into the Civil War. This rifle has the standard second variation markings and features and is dated "1838" on the breechblock. A collection number, "181," is in white on the bottom ahead of the trigger guard.