The massive, riveted steel frame represented the state of the art in 1911. Cast- and wrought-iron had been replaced first by Bessemer and later open-hearth steel sections. Major steel producers--Bethlehem and the Carnegie Steel Division of United States Steel--were competing to roll larger and larger sections, but riveted, built-up sections remained the norm. The double-height main banking room is visible at the ground floor of the new structure. The steel brackets at the fourth and fifth floor levels will ultimately support the stone cornices above the colonnades at Wall and Nassau Streets.