In the early 1800s, her and his brother Jake formed a family partnership as gun-makers in St. Louis. When Jake died in 1849, Sam continued producing the Hawken rifles until the late 1850s. The single-shot, muzzle-loading percussion rifles were renowned for their strength and reliability.

In 1859, Hawken turned over his business to his son William and headed for the gold fields west of Denver. William followed shortly afterward, actually producing a few rifles in Denver while in the West. In the interim, the St. Louis shop was run by William Watt, still using barrels made earlier by the Hawkens. In 1865, the shop was taken over by another gunsmith, John P. Gemmer, who continued the Hawken tradition well into the second half of the 19th century.