Samuel Pierpont Langley
Walcott became Secretary of the Smithsonian Institution in 1907 after the death of Samuel Pierpont Langley, holding the latter post until his own death. He was succeeded by Charles Greeley Abbot. Because of Walcott's responsibilities at the Smithsonian, he resigned as director of the United States Geological Survey. As part of the centennial celebration of Darwin's birth, Walcott was awarded an honorary doctorate by the University of Cambridge in 1909.