This two-day international conference will explore topics in Roman construction and design, urbanism, the impact of Hadrian, and more generally, the nature and legacy of Classicism. The conference commemorates the work of William L. MacDonald, FAAR’56 (1921–2010) who exerted a powerful influence on the field of Roman imperial architecture, shifting its study in significant new directions. The conference is organized by John A. Pinto, FAAR'75, RAAR'06, Howard Crosby Butler Memorial Professor of History of Architecture at Princeton University; Diane Favro, professor of Architecture and Urban Design at the University of California, Los Angeles; and Fikret K. Yegül, RAAR'98, professor of Roman Art and Architecture at the University of California, Santa Barbara. The conference is funded with grants from The Richard Driehaus Charitable Trust, The Graham Foundation for Advanced Studies in the Fine Arts, and the Andrew W. Mellon Foundation.