"I wake up every morning in a house built by slaves." After Michelle Obama said those words at the 2016 Democratic National Convention, thousands of Americans flooded the White House Historical Association with calls. Who were the enslaved African Americans who built the White House? This led historians from the Smithsonian's National Museum of African American History and Culture and the White House Historical Association on a years-long journey that turned up some interesting answers and even bigger questions.  Guests:  Lina Mann, historian, the White House Historical Association Mary Elliott, curator of American slavery, Smithsonian's National Museum of African American History and Culture