Once a year, skilled bricklayers build and fire a giant kiln – this one holds an astonishing 21,000 clay bricks – at Colonial Williamsburg, the world's largest living-history museum, in Williamsburg, Virginia, once the capital of Britain’s Virginia Colony. The bricklayers are not actors but experts and apprentices of the period trade. The re-created colonial city dates to the 1920s, when preservationists and philanthropists – notably John D. Rockefeller Jr. and his wife, Abby Aldrich Rockefeller, began accruing property.