There are a hundred and seventeen federal prisons in the United States, holding more than two hundred thousand prisoners. The security measures in Guantánamo can’t match those in the most locked-down of them, the ADX “Supermax” in Florence, Colorado. And that is only the federal system. Our jails may be crowded, but we’ve got plenty of them, of every description: by some measures, we are a nation of prisonkeepers.
Adam Serwer points out that each prisoner at Gitmo costs US taxpayers $800,000 per year.