This bayonet was designed to be used as either a bayonet or a sword, depending on the requirement at the moment of need.
They were manufactured from about 1849 to about 1854 and were used on a carbine or short-rifle, not a full-length musket.
It is believed these were used during the American Civil War when many European arsenals were emptied of their surplus arms.
They use a leather-covered wood scabbard, sheet-steel mounts (not shown).

NOTE: The muzzle locking-ring is missing from this example.