By the 1820s, Connecticut officials grew increasingly concerned that New-Gate was overcrowded, unsanitary, and unable to sustain itself economically, even though they had long judged its success largely by earnings and the number of escapes. Prison overseers warned that housing first-time offenders with hardened criminals turned New-Gate into a school for crime. Changes in Connecticut's criminal code in 1821 greatly increased the number of offenses punishable by imprisonment, and the prison population rose to a peak of 127 inmates. To address the swelling population and the inhumane underground living conditions, the state built a four-story cell block containing prisoner quarters as well as a granary, storeroom, offices, mess hall, and treadmill. Its completion allowed men and women to be separated, and the first female prisoner, Rachel Heddy, was admitted. Even after the new cell block was built, a committee reviewing the prison's operations concluded that New-Gate still was not an efficient state prison. Committee members and prison officials favored solitary cells, but the prison's infrastructure could not support solitary confinement. Because of these financial, structural, and sanitary problems, the prison closed in 1827, and about 120 inmates were transferred to a new facility in Wethersfield, Connecticut.