From 1955 to 1959, he was assistant director of the Wadsworth Atheneum. From 1959 to 1964, he was director of the Montreal Museum of Fine Arts. From 1964 to 1977, he was director of the Philadelphia Museum of Art. From 1978 to 1983, he was director of the Ackland Art Museum. From 1983 to 1993, he was director of the Cleveland Museum of Art. He won a 1991 Cleveland Arts Prize.