Some black leaders and scholars are accusing the National Park Service of dragging its feet on a congressional order to commemorate slaves kept by George Washington at the first presidential mansion.
Two years ago, Congress directed the park service to build a monument at the site, just steps from the Liberty Bell in Philadelphia's Independence National Historical Park, but it remains vacant and unacknowledged.
The commemoration would be the first federal memorial to slavery in the nation.
"We have to tell the truth, whether it hurts or not," said Charles Blockson, a curator of African-American artifacts at Temple University. "In the city of Philadelphia, it's never been told."
Park Superintendent Mary Bomar attributed the delays, in part, to disagreement among historians over the exact location where Washington's slaves once lived, as well as a lack of funding.