The first substantial prison built in what is U.S. soil today was established in 1570 by the Spanish in St. Augustine, Florida, although penal incarceration (imprisonment as a legal punishment for crime) was not a reigning principle of the day. Instead, traditional punishments—such as fines, penal servitude, whippings, and the stocks—and penal transportation were much more common. Sailing crews during the Age of Exploration were often padded with convicted criminals; Christopher Columbus’s first voyage in search of the West Indies included at least four of them. And by the 1600s, it was a regular practice for Britain to ship convicts to North America, either to help colonize or to be sold into indentured servitude, the most famous example of the former being the colony and future state of Georgia, which in the 1720s was settled almost entirely by convicts. The trend towards penal incarceration in the United States began after the American Revolution, where increased mobility, growing ...