The family moved to Philadelphia, where his father continued work on the Kentucky rifle, both an ornate sporting model and a basic version for the U.S.

[1] Henry Deringer moved back to Pennsylvania after serving his apprenticeship and set up shop in 1806 in Philadelphia, on Tamarind Street.

Using the basic flintlock action in common usage at the time, the pistols were muzzle loading single shots, or in some cases, double barreled in an over-under manner.

[1] For arms of his own design, he adopted the newer percussion cap technology, putting his pistol on the modern cutting edge.

[1] Further development and copying of his design resulted in the derringer (note the double-r) pistol that was generically manufactured widely by other companies.