The Smithsonian Castle was built in 1847. The historic structure sits in Washington D.C. and has recently been found to be built by slaves. Some of those slaves were owned by Martha Washington. There’s been a longtime search by historians to know which historic D.C. buildings were built by slaves. Two of the most notable buildings are the U.S. Capitol and the White House.
Anthropology professor Mark Auslander of Central Washington University discovered the building’s work order that listed “colored men” on the ledger. This was a common reference to slaves. Freed men would most likely have their names listed on the documents.
Auslander plumbed old Smithsonian ledger books, with the permission of Smithsonian officials, while he was a senior fellow at the National Museum of African Art last year. The sandstone, he learned, was bought from a quarry in the community of Seneca in Montgomery County. That quarry was owned by John Parke Custis Peter, a great-grandson of Martha Washington’s who had inherited slaves she once owned. (George Washington had famously freed his slaves in his will, but his wife retained slaves she had owned during a previous marriage.)