Fast Coexist has a very interesting series of graphics comparing the US prison population to other nations around the world. It writes:
The 2.2 million people who fill America's prisons exceed the entire population of Qatar. Yet, somehow, the fact of our mass incarceration rate tends to fade into the fabric of the everyday. Not so with a new tool from software engineer Stuart Sandine, who used data from the International Centre for Prison Studies to build a map of the world's imprisoned population.
With Sandine's Prison Data, it's easy to toggle among imprisonment stats in different countries. America's prison population exceeds that of China, Russia, Brazil, India, and Thailand, according to this data, and so does the land of the free's incarceration rate.
There's more at the link.
Here are a couple of the comparative maps from the series. Click each image for a larger view. First, comparing countries by total number of prisoners:
Next, comparing countries by total number of prisons:
There are many more maps at the link. Very informative.