House Minority Leader Nancy Pelosi (clockwise from top), Rep. John Lewis and the Rev. Patrick Conroy, chaplain of the House, congregate near a sandstone marker unveiled Tuesday in the Capitol Visitor Center’s Emancipation Hall commemorating the role of slave labor in the construction of the Capitol. The marker, quarried from Aquia Creek in Virginia, was once part of the East Front Portico, which was completed in 1826.