Material Type (s) Watercolor, ink, and pencil on paper drawing of "Mr. Robertson's Quarry near Aquia, ia", ca. 1806, from the Latrobe Sketchbooks, by Benjamin Henry Latrobe. In 1804, Latrobe was in the midst of designing and sourcing materials to build the U.S. Capitol building in Washington, D.C. His supply of sandstone was running out ...