Horace Grant
Pierson spoke with D. L. Moody at his Northfield Conferences and was also a speaker at the Keswick Convention who promoted holiness piety. During this period George Mueller and others had helped to change Pierson's eschatology from postmillennialism to premillennialism. As a missionary speaker A. T. Pierson influenced Robert Elliott Speer, Samuel Zwemer, Horace Grant Underwood and John R. Mott nobel peace prize winner to give their lives to missions.