U.S. Springfield Model 1842 muskets were manufactured at the Springfield Armory between 1844-1855. This model is significant as the last U.S. martial smoothbore musket, with known use in the Mexican-American War and the U.S. Civil War. "Eagle/US" marked center of the lock, "SPRING/FIELD/1848" at the tail of the lock, "V/P/eagle head" proofs at the left of the breech, "1848" (faint) dated barrel tang, oval script "JAS" (John A. Schaeffer) inspection cartouche on the left stock flat, and a "US" marked buttplate tang.