In 1991, construction in New York City revealed the intact graves of over 400 enslaved and free people of African descent buried under the streets of Lower Manhattan. Archaeological excavation of the site combined with historical research revealed it to be the largest colonial-era cemetery for African-descended people. With the help of local descendant communities, the site was preserved as a national historic landmark in 1993 and in 2007 it was designated the African Burial Ground National Monument, commemorating the site’s importance to the history of African descended people in colonial and federal New York City. Today, a visitor center on the site offers exhibits and events celebrating the contributions of free and enslaved Africans to the history of New York City