Roger W. Moss (1940-2025), emeritus director of the Athenaeum of Philadelphia, retired adjunct professor of historic preservation at the University of Pennsylvania, and longtime historian of the Carpenters' Company, devoted his life to preserving Philadelphia's rich architectural history and bringing to life the stories of the unknown master builders of the eighteenth century. He authored numerous publications, both individually and collaboratively, that contributed significantly to our understanding of historic architectural practices and influenced a new generation of architectural historians.