This small dirk or dagger dates to the first half of the 19th century. Place of origin - possibly Philadelphia or Baltimore. Tuite, Hartzler ascribe this particular style as a fighting dirk used by mariners I'm doubtful of that. Anyone concerned for their safety could've purchased a small personal protection weapon of this type.
Both the dirk hilt and the scabbard are silver. Ivory grip is nicely checkered, with no breaks or chips. Condition is quite good, with a nice patina. Overall length is 20 cm or 8". Blade is 11 cm/ 4 .5" long.
As with all  dirks of this type, the construction wasn't overly sturdy, and there is play between parts.