Ur Wikipedia: Incarceration in the United States
Although blacks account for only 12 percent of the U.S. population, 44 percent of all prisoners in the United States are black. Census data for 2000, which included a count of the number and race of all individuals incarcerated in the United States, revealed a dramatic racial disproportion of the incarcerated population in each state: the proportion of blacks in prison populations exceeded the proportion among state residents in every single state. In twenty states, the percent of blacks incarcerated was at least five times greater than their share of resident population.
Violent crime was not responsible for the quadrupling of the incarcerated population in the United States from 1980 to 2003. Violent crime rates had been relatively constant or declining over those decades. The prison population was increased primarily by public policy changes causing more prison sentences and lengthening time served, e.g. through mandatory minimum sentencing, ”three strikes” laws, and reductions in the availability of parole or early release. These policies were championed as protecting the public from serious and violent offenders, but instead yielded high rates of confinement for nonviolent offenders. Nearly three quarters of new admissions to state prison were convicted of nonviolent crimes. Only 49 percent of sentenced state inmates were held for violent offenses. Perhaps the single greatest force behind the growth of the prison population has been the national ”war on drugs.” The number of incarcerated drug offenders has increased twelvefold since 1980. In 2000, 22 percent of those in federal and state prisons were convicted on drug charges.