The United States has the largest prison population in the world, and the second-highest per-capita incarceration rate, behind Seychelles (which in 2014 had a total prison population of 735 out of a population of around 92,000). In 2013 in the USA, there were 698 people incarcerated per 100,000 population.his is the U.S. incarceration rate for adults or people tried as adults. According to the U.S. Bureau of Justice Statistics (BJS), 2,220,300 adults were incarcerated in U.S. federal and state prisons, and county jails in 2013 – about 0.91% of adults (1 in 110) in the U.S. resident population.