The American Institute of Architects Archives
There are few written records concerning 19th-century members who joined before the system of written membership application forms began. The AIA's membership file contains a notification from the Boston chapter about Vaughan's death. The AIA's Baldwin Memorial files contain copies of memorials about Henry Vaughan that were published in the October 1917 issue of the Journal of the American Institute of Architects, in Architectural Record, and in American Architect. Contact the AIA Archives at email@example.com for further information.
The Almighty Wall: The Architecture of Henry Vaughan, by William Morgan (MIT Press, 1982)