Just days after archaeologists on Maryland’s eastern shore uncovered what they believe to be the oldest settlement of African-Americans in the United States, another team in Philadelphia unearthed what may be the resting place of nearly 3,000 others under a playground in the city’s Weccecoe Park.

On Thursday, Douglas Mooney, senior archaeologist for URS corporation and his colleagues dug up a single white gravestone belonging to 26-year-old Amelia Brown, who was likely a member of the Mother Bethel A.M.E. Church, who bought the burial site as a private cemetery in 1810 and used it as such until 1864.