The jailers of the 19th century — even in the pre-Civil War South — largely abandoned the practice of imprisoning people for falling into debt as counterproductive and ultimately barbaric. In the 1970s and ’80s, the U.S. Supreme Court affirmed that incarcerating people who can’t pay fines because of poverty violates the U.S. Constitution. Apparently, though, some states and county jails never got the memo. Welcome to the debtors’ prisons of the 21st century. “Edwina Nowlin, a poor Michigan resident, was ordered to reimburse a juvenile detention center $104 a month for holding her 16-year-old son,” the New York Times...