From Lew Rockwell's Prisoner Nation:

There are 2.3 million people behind bars. China, with four times as many people, has 1.6 million in prison.

In terms of population, the United States has 751 people in prison for every 100,000, while the closest competitor in this regard is Russia with 627. I'm struck by this figure: 531 in Cuba. The median global rate is 125.

What's amazing is that most of this imprisoning trend is recent, dating really from the 1980s, and most of the change is due to drug laws. From 1925 to 1975, the rate of imprisonment was stable at 110, lower than the international average, which is what you might expect in a country that purports to value freedom. But then it suddenly shot up in the 1980s. There were 30,000 people in jail for drugs in 1980, while today there are half a million.