Great NPR series on solitary confinement

With thanks to How Appealing for this tip, I see that National Public Radio has started an interesting series on solitary confinement.  This article, entitled "In U.S. Prisons, Thousands Spend Years in Isolation," provides background and links for the series' audio segments.  Also, this addition piece, providing an "overview of key moments in the history of solitary confinement" in the United States, is a fascinating read.  Here is how the NPR timeline starts and ends:

1829 - The first experiment in solitary confinement in the United States begins at the Eastern State Penitentiary in Philadelphia.  It is based on a Quaker belief that prisoners isolated in stone cells with only a Bible would use the time to repent, pray and find introspection. But many of the inmates go insane, commit suicide, or are no longer able to function in society, and the practice is slowly abandoned during the following decades....

2005 - Daniel P. Mears, an associate professor at Florida State University, conducts a nationwide study and finds there are now 40 states operating Supermax or control-unit prisons, which collectively hold more than 25,000 U.S. prisoners.