Princeton University is led by a President selected by the Board of Trustees. Until the accession of Woodrow Wilson, a political scientist, in 1902, they were all Presbyterian clergymen, as well as professors. Former President Shirley M. Tilghman is a biologist; her two predecessors were economists. The official residence of the president of the university is the Walter Lowrie House. Prior to 1968, Prospect House served in that capacity.