There are roughly 2.3 million people in jails and prisons in America, more than any country in the world.
The United States has 756 people in jail per 100,000 people. No other country has more than 700, and only two are over 600 Russia (629) and Rwanda (604).
Of the 2.3 million people in American jails, 806,000 are black males. African-Americans--males and females--make up .6 percent of the entire world's population, but African-American males--alone--make up 8 percent of the entire world's prison population. I know there are people who think some kind of demon culture could create a world where a group that makes up roughly one in 200 citizens of the world, comprises one in 12 of its prisoners. But I kind of doubt it.
One final thought: If you released every black male in prison, our prison population would stand at 1.5 million, leaving us, still, with the second largest prison population in the world. Only China--a country with four times as many people--would have more (and barely--1.57 million). Russia would be a distant third with 890,000.