Son of a colonial gunsmith, Henry Deringer (1786-1868) began his business in Philadelphia and by 1810 was producing flintlock rifles, and government contracted muskets and military pistols. In 1825 he introduced the original Philadelphia Deringer, a single-shot muzzleloading percussion cap pistol, but it wasn’t until 1852 that the true percussion Philadelphia Deringer was fully developed and entered mass production. Deringer's small caplock pocket pistol became his most famous product, as it was easy to handle and accurate at short ranges. Because Deringer never claimed a patent for his pistols, there was widespread copying, including counterfeiting with his proofmarks copied and his name and trademark falsely applied. The derringer pistol, (with the double-r misspelling) grew out of widespread manufacture of Deringers by other companies. Deringer fought these infringements for most of his business life. The Deringer v. Plate ruling, in which the California Supreme Court ruled in the company's favor, became a landmark in trademark law.