The United states has 5% of the world's population yet 25% of the world's prison population.
This brings us to the question, how to reduce those numbers?
https://docs.google.com/spreadsheets/d/1K3DSydn3aTWATPtm1q7PImKgqbR56IYI3af7suBuULk/edit#gid=0 states how we can reduce our prisoner count pretty drastically. Some prisoners get freed, like those that are there for drug offenses, other crimes (like car theft) get less jail time and more of a rehabilitation approach. Other crimes (like murder and rape) the death penalty gets applied for. Repeal Kennedy vs Louisiana and Coker V Georgia so we can put rapists to death.
Combining these 2 things would reduce our prison population by around 70%, bringing our prison population more in line with the world average.