Landmarkism was a nineteenth-century Baptist movement arising in the South, west of the Appalachians, which asserted the sole validity and unbroken succession of Baptist churches from the New Testament era. This exclusivistic ecclesiology promoted the idea that the term “church” always refers to a local and visible institution. This emphasis on an unbroken succession of local and visible Baptist churches as the only true churches of Christ controverted the practices of ecumenism. Landmarkers believed that Baptists, who participated in “pulpit exchanges” with other denominations, accepted immersion performed outside the auspices of a Baptist church, or celebrated communion beyond the confines of local church membership, removed an ancient landmark that was essential to Baptist identity. These ideas deeply influenced Baptist life in the South. The more radical Landmarkers withdrew from participation in the Southern Baptist Convention, either forming their own organizations or maintaining a strict localism that forbade any denominational participation beyond the local church. Other Landmarkers remained within the Southern Baptist Convention, forming one of the major traditions in Southern Baptist life, especially in the late nineteenth and early twentieth centuries.
The dominant figure of the movement was James R. Graves of Tennessee, who was perhaps the most influential Baptist clergyman in the nineteenth-century South. James M. Pendleton of Kentucky and Amos C. Dayton of Mississippi joined with Graves in the promotion of Landmarkism. The three were known by their followers as the “Great Triumvirate.” Pendleton coined the term Landmark in an essay he wrote in 1854, which Graves published under the title An Old Landmark Re-set.
H. Wamble, “Landmarkism: Doctrinaire Ecclesiology Among Baptists,” Church History 33 (1964): 429-47