Mercersburg Theology was a German-American theological movement that began in the mid-19th century. It draws its name from Mercersburg, Pennsylvania, home of Marshall College from 1836 until its merger with Franklin College (Lancaster, Pennsylvania) in 1853, and also home to the seminary of the Reformed Church in the United States (RCUS) from 1837 until its relocation to Lancaster in 1871. History Although the seminary existed prior to 1844, Mercersburg Theology began in earnest in that year with the hiring of Philip Schaff to join John Williamson Nevin on staff at the seminary. Schaff sparked off controversy with his inaugural address, which was later published as Principle of Protestantism. This led to a series of articles written against Professor Schaff’s view by fellow RCUS pastor Joseph Berg. Several other magazines attacked Schaff and Nevin over their controversial position concerning the relation of the Reformed churches to the Roman Catholic Church. The RCUS was divided on the issue, as the Philadelphia Classis condemned Schaff’s theology, while the East Pennsylvania Classis defended it. The Synod took up the issue in 1845 and cleared Schaff and Principle of Protestantism by a vote of 37 to 3. This marked the only time Schaff was brought before the Synod on heresy charges; the Synod ruled that further complaints had to be registered with the Board of Visitors (trustees) of the Mercersburg Seminary, which never allowed any more complaints to go before the Synod for trial. The controversy did not end with the clearing of Professor Schaff, however. Professor Nevin published The Mystical Presence, a book about the Lord's Supper, in 1846. Nevin argued for an objective efficacy in the sacrament and that the atonement is brought about by the person of Christ, rather than his work. This brought about many reactions both from inside and outside the church, with the most famous critiques made by Joseph Berg and later by Professor Charles Hodge of Princeton Seminary, the latter a confessional Presbyterian. Spokesmen for both sides in the debate claimed fidelity to, and continuation of, the Reformed tradition. Nevin and Schaff advanced the movement further when they began the Mercersburg Review periodical in 1849. The publication provoked the departure of several prominent RCUS ministers and churches, including Joseph Berg in 1851, as well as the Germantown Reformed Church and its pastor Jacob Helfenstein, and the entire North Carolina Classis, all in 1853. During the 1850s the RCUS