Archeologists digging at a Philadelphia site where George Washington and his slaves once lived have unearthed portions of the president's house, a "long-shot" discovery that is already changing ideas about how the house was built.
Officials from Independence National Historical Park and the city announced Wednesday that a section of the kitchen wall as well the foundation walls from the main house had been unearthed at the site, about a block from Independence Mall.
Documentation about the house had led archaeologists to believe it had a one-story kitchen, but this week's find shows that a basement lay below the kitchen, possibly for storage, officials said.
The work is being done before construction of a new monument where the "President's House" once stood, intended to commemorate the daily life of the two presidents who lived there as well as the lives of the slaves.
Washington and John Adams each lived at the mansion between 1790 and 1800, when Philadelphia was the nation's capital. At least nine of Washington's slaves were also quartered there.
National Park Service archaeologist Jed Levin described the chances of any portion of the house having survived as "a long shot."
"In archaeology, you never know what you're going to find until you dig," he said in a written statement. "Now we're learning things we might otherwise never have known."
His team also found an 1833 coin in the basement floor of a house built over the site of the President's House, confirming historical records that Washington's residence was torn down in 1832.
The dig is expected to last through the end of May.
Construction will begin later on the monument, which will include a brick facade outlining the home's first floor and will hold video and audio exhibits about Washington and his slaves.