In USA, incarceration is the primary form of punishing the felons who commit crime. Incarceration is also the method by which the rehabilitation process is carried out. It is a shock as well as surprise to know that the largest prison population in the world belongs to the United States of America. The per capita incarceration rate is also the highest in the USA. There are state laws which are also known as territorial laws and there are United States federal laws. People who violate the state laws are sent to the state or territorial prison.