X is the library's major classification for books on religion. The collection covers the whole range of American religious experience, representing all religious denominations and sects, Christian and non-Christian. Among the many subjects classified within X are works on Adventists, Baptists, Congregationalists, deists, Episcopalians, Jews, Mennonites, spiritualists, and transcendentalists.
The collection is approximately 6,500 volumes strong. It consists primarily of books, and does not include, for example, the fifteen to twenty thousand individual sermons housed in the Pamphlets collections.
Four broad categories of religious material are cataloged under this classification. In the first category are American editions on theology, devotional literature, doctrinal works, and religious controversy for the period 1821-76. The Society collects comprehensively in this area. The second category includes non-American editions of religious works with strong relevance to American religious history. Particularly notable in this category are the seventeenth-century English editions of works by ministers and theologians like Ames, Shepard, and Davenport. Although the Society no longer actively collects such editions, this part of the collection is useful to the student of colonial religion. Many of our copies were originally owned by prominent American ministers. The third group of religious materials in the Society's collection are the imprints of the American mission presses, except those from Hawaii, which are shelved in the Hawaiian collection. Missionaries of the American Board of Commissioners for Foreign Missions as well as those of specific denominations established presses to spread the printed Gospel and other religious and educational tracts in the languages of the world's people. Notable examples of this genre in the collection are The Gospel According to John printed in Thai by the ABCFM Press at Bangkok in 1849, the first Peguan edition of The Life of Our Lord and Saviour Jesus Christ printed by the American Baptist Mission Press at Maulmain, Burma, in 1837, and An Alphabetic Dictionary of the Chinese Language in the Foochow Dialect by Robert Samuel Maclay, printed at Foochow by the Methodist Episcopal Mission Press in 1870. Finally, the collection includes secondary works of any publication date that treat the history of religious ideas, denominations, and movements in America through 1876.
Several other collections contain materials useful to the student of American religious history. The Mather Library, the Mather Collection, the Reserve Collection, and the Dated Books Collection each include significant works of theology and religion. Works treating the history of religion in particular states and cities, including histories and manuals of individual churches, and official publications of Bible societies, Sunday School unions, or other religious organizations, are to be found in the Local History and Institutions collections. Devotional works for children, catechisms, and many of the publications of the Sunday school and religious tract societies are included in the American Children's Books and Tracts collections.
- Richard C. Fyffe, former Senior Cataloger in the American Children's Books Project, and Doris O'Keefe, Senior Cataloger.