Benjamin Breckinridge (B. B.) Warfield (1851-1921) was a noted Presbyterian theologian, writer, and educator. He was born in Kentucky and studied at Princeton College and the University of Leipzig.
John Gresham Machen (1881-1937) was born in Baltimore, Maryland. He was a tremendous scholar who studied at Johns Hopkins and Princeton in the United States and at Marburg in Germany. Ordained in 1914 he became a professor of New Testament literature at Princeton Theological Seminary.
Donald Grey Barnhouse (1895-1960), a writer and pioneer in Christian radio, graduated from the University of Chicago and Princeton Theological Seminary.