The San Francisco Committee of Vigilance was a vigilante group formed in 1851. The catalyst for its formation was the criminality of the Sydney Ducks gang. It was revived in 1856 in response to rampant crime and corruption in the municipal government of San Francisco, California. The need for extralegal intervention was apparent with the explosive population growth following the discovery of gold in 1848. The small town of about 900 individuals grew to a booming city of over 20,000 very rapidly. This overwhelming growth in population made it nearly impossible for the previously established law enforcement to regulate any longer which resulted in the organization of vigilantes.