Jackson, Samuel Macauley, 1851–1912, American Presbyterian clergyman and encyclopedist, b. New York City. He was associate editor in the preparation of the original Schaff-Herzog Encyclopedia (1884) and editor in chief of the greatly enlarged New Schaff-Herzog Encyclopedia of Religious Knowledge (13 vol., 1908–14). He also edited the Concise Dictionary of Religious Knowledge (rev. ed. 1891) and the "American Church History" series (13 vol., 1893–97). Jackson was religious editor of several encyclopedias and dictionaries. He wrote a standard biography of Huldreich Zwingli (1901), part of the "Heroes of the Reformation" series, which he sponsored. He was long the moving spirit of the American Society of Church History and edited its papers.