This talk will summarize several of the main findings reported in my forthcoming book on the growth and consequences of incarceration in American over the last three decades. I will present evidence that incarceration has become a normal event in the lives of disadvantaged African-American men. Among those born since the late 1960s, serving time in prison has become more likely than college graduation or enrolling in the military. The emergence of mass imprisonment has contributed to a uniquely American form of social inequality. Imprisonment affects in inequality in two main ways: first by concealing large numbers of poor black men from conventional statistics on the economic well-being; second by diminishing the economic opportunities of ex-prisoners after release. These developments indicate that the prison boom has increased inequalities among blacks, and significantly diminished the quality of African American citizenship.