The penitentiary isn’t as old as it feels. Construction began in 1822, with the intent of providing for the separate and silent incarceration of housebreakers, forgers, highway robbers, horse thieves, and murderers from the eastern counties of Pennsylvania. Not only were prisoners to remain in their individual cells for the duration of their sentences, but once they passed through the portal their isolation was to be nearly complete. The board of inspectors for Philadelphia’s prisons at the time called for “such an entire seclusion of convicts from society and from one another, as that during the period of their confinement, no one shall see or hear, or be seen or heard by any human being, except the jailer, the inspectors, or such other persons, as for highly urgent reasons may be permitted to enter the halls of the prison.”

from Silence: A Social History of One of the Least Understood Elements of Our Lives by Jane Brox (Houghton Mifflin Harcourt)