The Essex County Jail, originally established in the early 19th century and designed by notable architect John Haviland, was a key correctional facility in Essex County, New Jersey. Its initial structure, influenced by the prison reform movement, emphasized natural light and prisoner rehabilitation, featuring large barred windows and skylights. Constructed from locally quarried sandstone and brownstone, the complex included a Warden’s House, a single cellblock, and was surrounded by a 12-foot wall. Over time, the facility expanded with additions such as a power plant, hospital, laundry, and multiple cell wings, eventually accommodating over 300 cells by the early 20th century[1][3][6]. The jail served as Essex County’s main detention center until 1970, when a newer facility replaced it. During its operational years, it was known for pioneering amenities like electricity, running water, and heating, which were uncommon in jails at the time. The environment was harsh, partly due to nearby industrial pollution. The complex also included a greenhouse and courtyard for inmates with good behavior, reflecting early attempts at rehabilitation[1]. Significant historical challenges included overcrowding, particularly in the 1980s at the Jail Annex in Caldwell, which housed up to 1,000 inmates in unsafe conditions, with prisoners crammed into spaces not intended for housing. The jail population often included many awaiting trial rather than convicted inmates[2]. The Essex County Jail played a role in broader social and legal shifts, notably during Prohibition and the War on Drugs, which dramatically increased incarceration rates, disproportionately affecting African-American populations. It also functioned as a detention center for various groups, including U.S. prisoners awaiting trial and those detained for short sentences without hard labor[4][5]. After closing, the original jail fell into abandonment, with parts of the complex damaged by fire in 2001. Its ruins remain a poignant symbol of historical penal practices, with ongoing studies considering its preservation or redevelopment[