The National Park Service began removing a slavery memorial at the President’s House in Philadelphia on Thursday afternoon -- an exhibit that opened in 2010 and honored the lives of the nine people held there who were enslaved by President George Washington. ABC News Philadelphia station WPVI captured video on Thursday afternoon of NPS staffers taking down boards and panels that told the stories of Austin, Christopher Sheels, Giles, Hercules, Joe Richardson, Moll, Oney Judge, Paris and Richmond. Michael Coard, a Philadelphia attorney who founded an advocacy group that fought for a slavery memorial at the President’s House for decades,...