Street then climbed into the cab of a green track hoe and, mugging for the cameras and under the guiding hand of operator Jeffrey Stamps, lowered the toothed bucket and took a foot-deep chunk out of the sod.
Though the $5.2 million memorial to the house shared by Presidents George Washington and John Adams when Philadelphia was the nation's capital is months from completion, the groundbreaking begins three to six weeks of intensive archaeological research - the first ever done on that section of Independence Mall.
Three Philadelphia high schools will have students taking part in studying archaeology and historical interpretation of artifacts and visiting the site during the excavation.
The public also will be able to get a close view through the wooden stage erected for today's ceremony, which will remain on site and let people view the dig.
Dennis Reidenbach, superintendent of Independence National Historical Park, said the park also plans to have a Web camera trained on the dig so Internet users can monitor the progress.
For Michael Coard, a Philadelphia lawyer and organizer of the Avenging the Ancestors Coalition, today's ceremony was vindication of a five-year campaign to get the National Park Service to include Washington's slaves in its commemoration of the President's House.
Coard and Street compared it to the same type of grassroots activism that helped end slavery itself.
Though Adams was an abolitionist who did not own slaves, Washington is believed to have brought nine slaves to Philadelphia from Mount Vernon in 1790: Oney Judge, Moll, Austin, Hercules, Richmond, Giles, Paris, Christopher Sheels and Joe.
Two of those slaves - Hercules, Washington's fabled chef, and Oney Judge, Martha Washington's personal maid - later escaped to freedom in Philadelphia.
Contact staff writer Joseph A. Slobodzian at 215-854-2985 or email@example.com.