Charles S. Greene, poet and former editor of the Overland Monthly, became librarian in 1899 and served until 1926. Mabel W. Thomas, who served as assistant librarian and chief reference librarian under Greene, and retired in 1948, began a collection of books, periodicals, and other material that were the foundation of the California Room in the 1940s and now contained in the well-used Oakland History Room.
Charles S. Greene, a poet and former editor of the Overland Monthly, became librarian in 1899 and stayed until 1926. Mabel W. Thomas, who worked as assistant librarian and chief reference librarian under Greene, retired in 1948 and started gathering books, periodicals, and other materials that would eventually become the core of the California Room in the 1940s, which is now housed in the Oakland History Room.