This thesis is an urban narrative that seeks to decipher America's prison system as it has been realized through the practice of architecture. By reading the texts of carceral architecture through its many representational forms-drawings of plan, elevation and section; actual buildings; paintings and photographs of those buildings-this essay works to disassemble tacit assumptions concerning America's ideological validation of the prison system. America's founding fathers theorized a new prison system through autonomous political and architectural discourses. Eventual prison practices that emerged from theories of prison reform contrasted greatly with initial reform principles. In part, this essay exposes the ways in which America's penal theorists used architecture to manufacture and reify the treatment of a criminal class. As penal theories became a material reality, part of the plan was to create an intrinsic architectural design that could operate clandestinely, rendering certain practices invisible. Furthermore, it was the division between actual buildings, and preceding discourses about building, and the ways in which these two realms reciprocally supported one another, that enabled a shift in ideology, making prison space common, universal and necessary. A successful city can be defined in part by how efficiently its rulers organize its citizens. America's early efforts to discover better ways to organize bodies produced a new type of carceral environment. Building a better prison meant building a better city, which in turn meant building a better nation. Philadelphia's battle with New York for urban supremacy included a contest to build the best prison. Prison architecture as a sign of urban supremacy suggests that a city can be read not just in its architectural splendor but also in its degree of success in the context of social control. Philadelphia understood its new prison architecture to be a refinement of what had previously existed. I insist that penal reform, expressed through Philadelphia's institutionalization of spatial segregation, was in no way a fine-tuning of social discipline. Rather than honing the techniques of social discipline, prisons and penitentiaries were ruptures in a productive social structure. Builders of America's first prisons and penitentiaries mobilized in space a new reality. As a result of consistent failures over the past two hundred years, America's prison system needs to be addressed in a profound way. This essay begins in a small way to correct what has become a systemic social mistake. I am demonstrating how architects unwittingly participated in faulty ideological formation, and I am suggesting that architects now sever themselves from this fatal trajectory.