A Pulitzer Prize-winning book on a brutal aspect of U.S. history has reignited debate on the country's racial past just as the country's first black president is seen as evidence of racial progress.
"Slavery By Another Name" recounts the little-known story of how in the decades after President Abraham Lincoln's 1863 Emancipation Proclamation to free slaves, hundreds of thousands of black Americans were re-enslaved as convict laborers.
Author Douglas Blackmon said on Tuesday the story was "absolutely essential" to understanding why a U.S. racial divide still exists and why the country's black minority lags behind the rest of the population in terms of economic and social health.
The convicts were arrested under laws such as vagrancy designed to ensnare them. They were then leased back to pay off their debts by working in coal mines, steel mills and other industries that flourished across the South.
Many were kept in chains and the book cites examples of a resurgence of some of the hallmarks of slavery: convicts kept in atrocious conditions, beatings, the use of dogs to track down escapees and murders by 'owners' that went unpunished.
Most of the people caught in the system were black men, though a few were white or black women.
Segregation, share-cropping and lynching are relatively well-known features of life in the U.S. South after the Civil War, but Blackmon said "neo-slavery" is largely neglected.
Even so, it exerted a powerful influence, terrorizing a swathe of the population and suppressing opposition to other forms of racial oppression.
Since the book was published, many black Americans have come forward with stories of forbears who were convicted and then effectively enslaved after the Civil War, Blackmon said.
"It has unleashed a conversation among ... African Americans thirsty for an explanation of how on earth could 10 million black Americans have remained through poverty and subjugation through this period of time," he said.
A leading historian of the period, Wayne Flynt, described the book as "right on target" and said business leaders worked to stamp out opposition from church leaders and others to convict leasing.
Two books about America's troubled racial past won Pulitzers this week, the other being "The Hemingses of Monticello: An American Family" by Annette Gordon-Reed, which deals with a slave family whose blood line is mixed with that of America's third president, Thomas Jefferson.
Blackmon said the books showed a renewed appetite to re-address forgotten aspects of the U.S. past in a new racial climate in which Barack Obama was elected president last year.
An abandoned coal quarry outside Birmingham, Alabama, shows the obscurity in which convicts toiled and died.
A century ago the Pratt Mines on what is now the outskirts of the city were a hive of activity. Thousands of men worked underground. Rail cars hauled coal from the earth and a whole town, called Pratt City, grew up to support the industry.
Now the mine is covered by dense forest that hides the unmarked graves of hundreds of convicts.
The graves appear as shallow depressions in the soil where coffins and corpses decomposed and collapsed inward.
A few are set off with a small slab of alabaster or marble, and on some there are plain headstones. Reads one gravestone: "DIED JULY 5 1910, AGED 40." Its top half is broken off after a century of neglect so the identity of the person buried there can never be known.
Few people, even from the local neighborhood, are aware of the unofficial cemetery, said Jack Bergstresser, director of Alabama's Museum of Iron and Steel, who first located the site using an old map.
"It's safe to say that graveyard is forgotten," he said, arguing that because the laborers were convicts and thus disgraced, few blacks or whites want to remember them.