"At Shelter Island on New York's Long Island, archaeologists have spent several years peeling open the grounds of present-day Sylvester Manor to reveal the traces of an 8,000-acre plantation that provisioned two sugar plantations in Barbados and made heavy use of African slave labor. During the late 1600s, at least 20 slaves there served as carpenters, blacksmiths, domestics and field hands.Some of the new evidence of Northern slaveholding plantations comes from excavations on the well-manicured grounds of historic estate homes, like the elegant Van Cortlandt Manor on the banks of New York's Croton River, where slaves worked in the fields and orchards.
Other discoveries are turning up in more humble, more endangered locations. In Morris County, N.J., plans for a park-and-ride transit station for New York commuters recently prompted the state to order archaeological investigations of the site, thought to have been home to the 18th century Beverwyck estate."
During excavations of the new [Liberty Bell] center, archaeologists recovered thousands of artifacts from the red brick mansion where Washington stayed in Philadelphia. But it took public protests for the National Park Service to decide that the story of Washington's slaves deserved space in the pavilion, too.
"Most Philadelphians would be shocked to know that Washington had slaves with him in the city," said University of California, Los Angeles, history professor Gary Nash, who helped spur the Park Service decision.
Well, I’m tw0 for four on those locations: I used to rent a house on Sheter Island in the summers during the ‘80s and ‘90s and know that excavation. And, I live and work in Morris County NJ, and I am currently sitting near Beverwyck road.