By Jane Beresford
BBC producer of I Too Am America
The remains of 20,000 Africans are said to be buried under New York
The remains of 20,000 African men, women and children have lain beneath the busy streets of New York for 300 years, waiting to tell their stories on the extent of slavery in the city.
In March 1992, leading African-America archaeologist Michael Blakey arrived at the burial ground in downtown Manhattan.
"I had read about these people documented as chattel, " he said. "Now I was going to learn about these Africans in New York as human beings."
A haunting sight greeted him. Being winter, work was taking place under a translucent plastic tent.
"I'd really never seen an excavation like that one," he said. "There were mini excavators working and kerosene heaters going."
"By the time I got there, about a dozen burials were in the process of being exposed. One could see very clearly the positions that were meant to put them at peace when they were buried."
Many had their arms crossed. One female skeleton had tiny bones by her side, suggesting a woman cradling a new born child.
Sign of slavery
They had devastating secrets to share, information that would reveal the extent of slavery in New York.
"Quite early on, we found the skull and thorax of an individual with filed or 'culturally modified' teeth - and that stunned me because that is very rare," Mr Blakey said.
There are only about nine skeletons in the whole of the Americas that have been discovered with filed teeth, he said.
African slaves helped create the city
"In the African burial ground we found at least 27 individuals with filed teeth."
This suggested these people had come to New York directly from Africa before importation was banned in 1808 and American slaveholders started "breeding" slaves on the plantations in the South.
"These kinds of irreversible identifiers put people at risk who might want to escape," Mr Blakey said.
Runaway adverts in newspapers seeking to re-capture the many escaped enslaved Africans often mentioned dental modification, he said - so no one would not choose to have that kind of marker.
'Worked to death'
But these enslaved Africans helped create the city of New York. They worked as stevedores in the docks and as labourers building the fortification known as Wall Street, which protected the city against attack from Native Americans.
Evidence from the burial site revealed, for the first time, the enormous human cost of such work.
Half of the remains were of children under the age of 12. Women were usually dead by 40.
"It seems that it was cost effective for slave traders to work people to death and then simply to replace them, so they sought to get Africans who were as young as possible, but ready to work," said Mr Blakey.
From royalty to slavery?
The woman designated "Burial 340" was a very intriguing person.
"She was in her 40s - and for the burial ground population that makes her kind of old", said archaeologist Sherrill Wilson, now director of interpretation at the African Burial Ground.
"Around her waist the woman wore a belt of over 100 beads and cowrie shells," she said.
"In some parts of Africa in the 1700s, it's illegal for people who are not members of royal families to own even one of these beads - and she has over 100 buried with her," she added.
Such treasures are known to belong to Akan-speaking people. Had this woman been born into royalty in Ghana and died a slave in New York City?
And who chose to bury her with the waist belt of beads?
"These are very valuable items," said Ms Wilson. "It implies that whoever buried her... could have chosen to sell those items to feed themselves - but they made the choice to bury them with her."
Perhaps it was a tradition, a rite, or an act of defiance against those who had enslaved a woman of noble birth.
The skeletons of 18th Century slaves have spoken to those living free today to remind us that New York - one of the world's great immigrant cities - destroyed as well as created destinies.
The Archive Hour: I Too Am America was broadcast on Saturday 24 April on BBC Radio 4 at 2000 BST.