12,501 of these rifles were manufactured by Remington between 1862-1865 during the Civil War for the Union. Government records listed them as "Harpers Ferry Pattern" rifles, and they have similarities to both the Model 1841 and Model 1855 rifles that were manufactured at Harpers Ferry prior to the Civil War but are of a unique pattern. Whether or not any of these rifles saw use in the war remains unclear and debated. "1863" dated lock and barrel. Left stock flat marked with boxed script inspection cartouches "HDJ" (Henry D. Jennings) and "BH" (Benjamin Hannis). "H.S.L" (Homer S. Lathe) inspection initials marked on the left barrel flat at the breech.