As the twentieth century came to a close and the twenty-first began, something occurred in the United States that was without international parallel or historical precedent. Between 1970 and 2010 more people were incarcerated in the United States than were imprisoned in any other country, and at no other point in its past had the nation’s economic, social, and political institutions become so bound up with the practice of punishment. By 2006 more than 7.3 million Americans had become entangled in the criminal justice system. The American prison population had by that year increased more rapidly than had the resident population as a whole, and one in every thirty-one US residents was under some form of correctional supervision, such as in prison or jail, or on probation or parole. As importantly, the incarcerated and supervised population of the United States was, overwhelmingly, a population of color. African American men experienced the highest imprisonment rate of all racial groups, male or female. It was 6.5 times the rate of white males and 2.5 times that of Hispanic males. By the middle of 2006 one in fifteen black men over the age of eighteen were behind bars as were one in nine black men aged twenty to thirty-four. The imprisonment rate of African American women looked little better. It was almost double that of Hispanic women and three times the rate of white women. 1

Despite the fact that ten times more Americans were imprisoned in the last decade of the twentieth century than were killed during the Vietnam War (591,298 versus 58,228), and even though a greater number of African Americans had ended up in penal institutions than in institutions of higher learning by the new millennium (188,500 more), historians have largely ignored the mass incarceration of the late twentieth century and have not yet begun to sort out its impact on the social, economic, and political evolution of