The Folsom State Prison was constructed in 1880, due to over-crowding that occurred at California’s oldest prison, which is north of San Francisco, the San Quentin Prison. Eventually dams were constructed in the San Francisco and the Sacramento regions. In order to lower the cost of the construction of the dams, prisoners from the Folsom and the San Quentin prisons were brought to assist with the hard labor.
The prison had a facility to hold “insane” and “deranged” criminals. However the facility, called “The Bug House” was never used.
Several armed riots occurred during the course of the prison history, hence creating the need for watchtowers and for gun shields.
The most violent revolt that occurred at the Folsom Prison was in 1937.