The change began with little official notice or fanfare. There were no presidential speeches to Congress, such as the ones pledging to land a person on the moon within a decade or declaring war on poverty. No catastrophic event, such as the attack on Pearl Harbor or 9/11, mobilized the United States. No high-profile commission issued a wake-up call, as the Kerner Commission did in warning the nation that it was moving toward two separate and unequal societies and, decades later, as the 9/11 Commission did in exposing the country's vulnerabilities to terrorism. Indeed, to see the change of interest – the massive buildup of the U.S. prison population that began in the 1970s – one has to look to the statistical record. There was little bark (at least at first), but a great deal of bite.

Beginning with modern record keeping in 1925 and continuing through 1975, prisoners represented a tiny segment of the U.S. population. In 1925, there were 92,000 inmates in state and federal prisons. By 1975, the number behind bars had grown to 241,000, but this increase merely kept pace with the growth of the general population. The rate of imprisonment remained stable, at about 110 inmates per 100,000 residents.