Professor de la Yale University (1938-83). Especialitzat en arquitectura moderna espanyola, publicà Arquitectura de los siglos XVII y XVIII (Ars Hispaniae, 1957) —amb Martin S.Soria—, Art and Architecture in Spain and Portugal and their American Dominions, 1500-1800 (1959) i Building the Escorial (1982). També estudià l’art precolombí: The Art and Architecture of Ancient America (1962) i Studies in Classic Maya Iconography (1962).