He served as the chairman of the History of Art and Architecture Department (1989–94, 1997–99).
Morgan's books include Boston Architecture, 1975-1990 (co-authored with Naomi Miller), Charles A. Platt: The Artist as Architect, and Shaping a New American Landscape: The Art and Architecture of Charles A. Platt.
Morgan is the editor and one of the principal authors for Buildings of Massachusetts: Metropolitan Boston (a volume in the Buildings of the United States series sponsored by the Society of Architectural Historians).
Morgan was the architecture editor for The Encyclopedia of New England.
Morgan was president of the Society of Architectural Historians from 1994 to 1996.