The original plaster model, shipped from Rome to the United States in five main sections, was used to make the mold for the final bronze that stands atop the Capitol. Clark Mills cast the statue in his foundry at the edge of the District of Columbia from 1860 to 1862. It was made by pressing the pieces into fine, moist sand to create a negative. After a core was formed, molten bronze was poured into a half-inch space to create the hollow figure. Fifteen thousand pounds of copper, 1,500 pounds of tin, and 200 pounds of zinc were needed to cast the 19 ½-foot statue.
One of Mills’s most valued assistants was his highly skilled slave Philip Reid, whom he described as “an expert and admirable workman.” Reid and the other slaves in Mills’s foundry were paid only when they worked on Sundays. After he was emancipated in 1862, Reid assisted Mills during the moving and temporary placement of the bronze statue on the Capitol grounds.
Photograph by Mathew Brady, National Archives and Records Administration, Washington, D.C.