In 1823, Philadelphia city leaders began a unique project, to build the largest and most expensive building ever built in the young nation: Eastern State Penitentiary.

It was to be a new kind of prison, a structure where hundreds were confined in complete and uninterrupted solitary confinement for years on end. It was to be an experiment: to use architecture and isolation as tools of social control.

Cellblocks one, two, and three opened in succession. Each block had 38 cells along a vaulted corridor. There were to be seven blocks, for a total of 266 cells.

The Declaration of Independence promised: “All men are created equal.” The U.S. Constitution promised we must: “Secure the Blessings of Liberty to ourselves.” In this same city within site of the place where these documents were signed, work began on a project that would accomplish the exact opposite: confinement instead of liberty, punishment instead of freedom.

Already the city of Philadelphia was doubling in population every few years: a city of immigrants, escaped slaves, convicts, and Quakers. Eastern State was already too small. Plans changed by 1831 to increase capacity. Cellblocks four, five, six, and seven each had some one hundred cells.

By 1836, the prison was complete: 600 cells for solitary confinement. Men, women, and children locked away for years on end. Some for murder, most for crimes committed out of desperation: the theft of food, clothes, and money to survive in a nation that had no welfare state, no social safety net.

From the outside: the prison resembled a medieval castle. Walls twelve feet thick. Turrets. Barred windows. A tower 85 feet tall, visible for miles around. The architecture was a warning to those who passed: break the law and you will be punished behind these walls.

From the inside: the prison resembled a perfect circle. All cells radiating from a central watchtower, one guard empowered to survey hundreds of inmates in the sweep of an eye. Beneath the guard tower: a library. Knowledge of the law, of the Bible, of inmates made possible through architecture. The surveillance state brought under one roof.

Each cell: A cube 12 feet by 7 and one half feet, with an adjacent individual exercise yard. Food was fed through a small hole in the wall. Guards wore padded slippers, so that prisoners could not hear them coming. Inmates were given only one book and maybe another: the Bible, in hopes that reading it would inspire guilt and shame. Silence ruled.

Charles Dickens described the inmates of Eastern State in 1842: “He is a man buried alive; to be dug out in the slow round of years; and in the mean time dead to everything but torturing anxieties and horrible despair.”

Corridors hundreds of feet long, modeled after the form of a medieval cathedral. A cathedral not for God, but for the state. A monastery not for monks, but for prisoners.

Solitary confinement did not work. Some victims went insane. Others were abused by guards: tied to the radiator pipes and burned by the heat, confined in total darkness for weeks on end.

Solitary confinement ended. The experiment failed.

But Philadelphia kept on growing. Slavery was abolished after the Civil War, “except as a punishment for crime.” Unpaid inmate labored to make shoes, furniture, and clothes turned a profit for the prison.

Two new blocks were added by 1879. The oldest blocks one, two, and three were expanded. New cells did not include individual exercise yards. Two more blocks were added by 1904.

A powerhouse produced heat, hot water, and electricity for all cells.

A kitchen made thousands of meals a day.

An industrial building became sweatshop for hundreds of inmates.

Block 12 opened by 1911. The older blocks were one floor. This block was three floors. Space was running out.

Block 13 opened, once again for solitary confinement. For breaking further rules while in prison, inmates were punished in underground cells, without light, food, or fresh air.

Block 14 opened by 1927. Built by the prisoners’ own labor and wedged in an awkward angle.

More offices were added. More sweatshops were built.

Block 15 opened by 1959: A maximum-security space for inmates waiting to be executed.

Designed for just 266 inmates. Now home to almost one thousand. The place was overcrowded and aging, inmates now had little space to move, limited access to resources. After 150 years, Eastern State Penitentiary closed in 1971.

Since then, America’s incarcerated population keeps on growing. It is now the world’s largest and most expensive system of prisons and jails. It confines not hundreds in solitary confinement, as Eastern State envisioned. The modern American system confines millions behind bars.

As we reflect on Philadelphia as birthplace of American Democracy, “City of Brotherly Love,” city of the American Revolution…

The architecture of Eastern State Penitentiary reminds us: Forced labor and confinement are as old as the American nation state.