There is a lengthy article in today's New York Times which mentions that the U.S., with less than 5% of the world's population has 25% of the world's official prison population. The article looks at both causes and criticisms, from mandatory sentencing to the high level of violence in the society connected to the absence of gun control, to the flooding of jails and prisons with minor drug offenders.
These are all significant points, but there are also others. Crime, serious sociologists have told us for a very long time, is connected to destitution poverty. "Backward" societies seek to cope with crime through draconian, often religious based legal codes and various forms of local vigilante activities to control criminals. Advanced societies construct "welfare states" providing for a social safety net for the poor, attempt to make incarceration serve the interest of rehabilitation, and then seek to re-integrate offenders into society as effectively as possible, letting them maintain their basic civil rights and find gainful employment.
The United States since the end of the 1960s has built with critics call a "prison industrial complex" to compliment its military industrial complex and to substitute for the national "war on poverty" which Lyndon Johnson proclaimed in 1964 and then failed to fight after he escalated the Vietnam War in 1965.
As for a "welfare state," it existed only in a limited way in the U.S. and has been subject to relentless attack by Ronald Reagan and his successors since 1980. As a result, the number of Americans in prisons and jails has increased by four times since the 1970s and at present is one fourth of the official prison population of the world.
In a very basic way, this is an example of the horror that rightwing rule has produced in the U.S. over the last thirty years. Freedom, liberty and democracy as slogans in a society that has one fourth of all the world's prisoners. The richest society in the world with more really poor people than any rich society in the world. If this is the triumph of capitalism, can you imagine what its defeat would be?