<P> The Cook County Jail, located on 96 acres (39 hectares) in Cook County, Illinois, is the largest single site jail in the United States . Located at 2700 South California Avenue in the city of Chicago, it houses about 6500 prisoners and employs 3900 law enforcement officials and 7000 civilian employees . </P> <P> The jail has held several well - known and infamous criminals, including Tony Accardo, Frank Nitti, Larry Hoover, Jeff Fort, Richard Speck, John Wayne Gacy and the Chicago Seven . </P>

What's the largest jail in the united states