New York opens slave burial site
A museum is also planned for the site
New York Mayor Michael Bloomberg and poet Maya Angelou attended a dedication ceremony for a monument at the site.
The late 17th Century burial site was gradually built over as New York expanded, but was rediscovered during an excavation in 1991.
Some 400 remains, many of children, were found during excavations.
Half of the remains found at the burial site were of children under the age of 12.
The entire project has cost more than $50 million (£24 million) to complete.
The burial site in Manhattan was rediscovered during excavations for a federal building.
Now a 25ft (7.6 metre) granite monument marks the site.
It was designed by Rodney Leon and is made out of stone from South Africa and from North America to symbolise the two worlds coming together.
The entry to the monument is called The Door of Return - a nod to the name given to the departure points from which slaves were shipped from Africa to North America.
"The tragedy was that for so many years, for centuries, people passing by this site did not know about the sacrifices they [the slaves] had made," Mr Leon said.
"Now we have an opportunity to right some of the wrongs of the past."
Enslaved Africans helped create the city of New York.
They worked in the docks and as labourers building the fortification known as Wall Street, which protected the city against attack from Native Americans.
Mayor Michael Bloomberg said that the excavations had revealed "one of the most uncomfortable and tragic truths in our city's history. For two centuries, slavery was widespread in New York."