The Model 1819 Hall was the first U.S. military breech loading firearm issued in large numbers and also the first firearm manufactured with totally interchangeable parts. In 1819, John H. Hall would enter into a contract with the War Department for 1,000 of his breech loading rifles. Hall would occupy an old armory sawmill on the Shenandoah River next to the Harpers Ferry Armory, which would come to be known as Hall's Rifle Works. It took Hall some five years to get the proper tools and water powered machinery assembled to produce the rifles. This example, dated 1826, is included as part of his second completed contract of 1,000 rifles. To prove these rifles were truly parts interchangeable, 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. Though they suffered from gas leak and other issues common to early breechloaders, the Hall rifles and carbines remained in use through the Civil War. Model 1819 Hall breech loading rifles are described on pages 465-473 of George D. Moller's book "American Military Shoulder Arms Volume II", with this exact rifle photographed on page 465, and its breech block photographed on page 470, in which the caption states, "The lower rear portion of the breech block of rifles made from 1826 has been cut away, resulting in a concave lower profile. The shoulder in the front of the cock was eliminated." This rifle has the standard offset blade and notch sights, "J. H. HALL/H. FERRY/US/1826" marked breechblock, barrel band retaining springs, and a proper button head ramrod. "GDM" (George D. Moller) collection initials marked at the toe of the stock. Includes socket bayonet, leather sling, and wood tampion. Provenance: The George Moller Collection