Mary Looman and John Carl's thesis is straightforward: The human population embroiled within America's criminal justice system is so large, the geographic space it occupies so vast, and the social processes it undergoes so distinctive, that it has produced a cultural heritage all its own. As such, the masses entering, occupying, and cycling out of America's prison system ought to be understood as if they were members of a distinct nation. Hence their book's title: A Country Called Prison.

Since the 1970s, America's total prison population—state and federal combined—has leaped from about 300,000 to more than 1.5 million. Yet physical walls and razor wire fences do not bound the country called prison. As Looman and Carl explain, "if all individuals who are currently under some form of government supervision—via parole, probation, prison and local jails—are included, that number explodes to more than 6.9 million," a population just below Bulgaria's. And the nation is even larger than that, since inmates' broader families and social networks are deeply shaped by incarceration's cultural effects.