The Julian Parks Boyd subseries contains the records of Julian Parks Boyd, who was Princeton's University Librarian 1940-1952. His tenure was a period of immense growth in the Library, both in terms of collections and facilities. As with the records of earlier University Librarians, these records contain correspondence and subject files pertaining to acquisitions, budgets, and other routine administrative matters. This series is also notable however for its illustration of the Library's growing importance to the University, as conveyed by the records which pertain to the planning and construction of Firestone Library, found primarily in the Cooperative Committee on Library Buildings files (Box 26-27).

The records in this subseries also give some clue as to the rising stature of the Library outside of the immediate University community, as demonstrated in the ample correspondence between Boyd and the American Library Association, the Association of Research Libraries, and other nationally-organized professional and cultural organizations. Also contained within the records is correspondence between the University Librarian and notable writers (H. L. Mencken, Alan Tate), and publishing houses (Doubleday, Scribner's) regarding the acquisition of papers and records for the Library's special collections. Boyd's attention to special collections is also represented by files pertaining to his role in the formation of committees on Archives of American Letters, Architecture, and Dramatic Art, found under the broad folder heading of Archives of American Civilization.