The Hounds were a nativist or anti-foreigner gang of San Francisco which specifically targeted recently arrived immigrants, particularly Hispanic Americans, during the California Gold Rush of 1849.
They were West Coast counterparts of New York's Bowery Boys, Officially called the San Francisco Society of Regulators, the gang, mostly made up of thugs and criminals as well as former Mexican–American War veterans, would later become known as The Hounds.
Controlled by the "Know Nothing" political party, the gang used patriotism in the aftermath of the Mexican–American War to drive foreigners from the recently discovered gold fields.
The Hounds had early popular support despite their brutal tactics, as many of the gang attacked unarmed Mexican and Chilean immigrants in Clarks Point and extorted money from those few who were successful.
Leavenworth along with Sam Brannan, Captain Beezer Simmons, and other citizens demanded the city take action and later 230 men were deputized to arrest the Hounds.