From the establishment of the Walnut Street Jail in Philadelphia (1790) through the development of the Auburn, N.Y. (1817), and Pennsylvania (1829> systems, the well-ordered, physically isolated prison was viewed as a mechanism to instil discipline, remove temptation, and rehabilitate the offender. In the Auburn system, prisoners were housed in separate cells at night, but worked together during the day; the Pennsylvania system isolated the offender for the entire period of confinement. Both systems, however, were based on the premise that isolation, the substitution of good habits for sloth and crime, and a regimen of silence, penitence, and labour would return the offender to society cured of vices and ready to become a responsible citizen.
Largely because it was a more effective way of harnessing the labour power of prisoners and was thus less costly to adopt, the Auburn system became the dominant method of confinement in the United States. The goal of reformation was eventually shunted into the background-prisoners became holding operations, designed to promote a respect for order and authority.
The National Prison Conference, held in Cincinnati, Ohio, in 1870, was the first signal of reform. Encouraged by the recent development of PROBATION and PAROLE, the conference called for the establishment of the indeterminate sentence, which allows a court to specify, within statutory limits, the minimum and maximum length of sentence for a particular offence. It was believed that this type of sentence would give the offender an incentive for rehabilitation, for he or she would be released only when it was determined that satisfactory change had taken place.
In recent years, however, rising crime rates have thrown into question the effectiveness of prison rehabilitation, and several states have re-turned to mandatory sentencing laws whereby the convict must serve a term of specified length.