This pie chart, by Prison Policy Initiative, breaks down where and why 2.3 million people in the US are behind bars. One in five of them are imprisoned for non-violent drug offenses. "For the last 20 years, the number of arrests for drug sales have remained flat, while the number of arrests for possession have grown."
While this pie chart provides a comprehensive snapshot of our correctional system, the graphic does not capture the enormous churn in and out of our correctional facilities and the far larger universe of people whose lives are affected by the criminal justice system. Every year, 641,000 people walk out of prison gates, but people go to jail over 11 million times each year. Jail churn is particularly high because most people in jails have not been convicted. Some have just been arrested and will make bail in the next few hours or days, and others are too poor to make bail and must remain behind bars until their trial. Only a small number (187,000 on any given day) have been convicted, generally serving misdemeanors sentences under a year.