The Andover-Harvard Theological Library at the Harvard Divinity School in Cambridge, Massachusetts, has a feature titled “Ask a Research Librarian.” On Feb. 15, 2011, the question was asked: “Do you have any special collections related to Theosophy?” Here is the reply:
The Andover-Harvard Theological Library does have one of the largest collections of 19th c. Theosophical literature. The books, which are cataloged in HOLLIS, came mostly from members of the former Theosophical Society in America. We also have letters of an important Theosophical leader—Helena Petrovna Blavatsky. The Blavatsky collection includes correspondence between Madame Blavatsky and William Quan Judge, who was general secretary of the American Section of the Theosophical Society. Background information about these letters appeared in the October-January, 1992-1993, double issue of Theosophical History, and the letters themselves were transcribed and published in volumes 5-6, 1994-1996, of this publication. For more information about Theosophy sources, see Theosophy in the Nineteenth Century: An Annotated Bibliography (1994).
The Theosophical Society in America referred to was one of the independent groups that emerged from Judge’s American Section of the TS, not the present organization of that name. It's membership derived from those who were not willing to follow Katherine Tingley as leader. The group published the Theosophical Quarterly from New York from 1903 to 1938.