and promoting letters by original research and effort.” The Secretary was also expected “to act as a respected channel of communication between the institution and scientific and literary individuals and societies in this and foreign countries.” The regents chose Joseph Henry, who might have been America’s most distinguished scientist at the time. Henry later served as second president of the National Academy of Sciences, which he had helped President Lincoln to establish.
Henry strongly promoted research as the key focus of SI. Although the act of Congress establishing SI directed the Institution to have a library, a museum, and an art gallery, Henry believed that it should have such a charge only temporarily and that the management and operation of these entities should be transferred to other agencies as soon as possible. However, through the efforts of the then Assistant Secretary Spencer Fullerton Baird, the Smithsonian began to receive major natural history and cultural collections that document the minerals, fossils, rocks, animals, and plants of North America, which ultimately grew to be the best collection of its kind in the world. Baird succeeded Henry as Secretary in 1878 and embraced the museum mandate he favored for the Institution. Under Baird, research and public activities centered around natural history.
In 1887, Samuel Pierpont Langley, a prominent and internationally respected scientist in astrophysics and aeronautics, was appointed the third Secretary of SI. Under his leadership, the balance of Smithsonian interests tilted toward the physical sciences. Langley established the Smithsonian Astrophysical Observatory and the departments of biology, anthropology, and geology.
In 1907, Charles Doolittle Walcott, one of the leading paleontologists of the time, began a 20-year term as Secretary. The return to prominence of natural history research at SI culminated in the opening of the National Museum of Natural History to the public in 1910. Under Walcott’s leadership, the Smithsonian also participated in a major biological survey in the Panama Canal Zone, an effort that led to the establishment of the Smithsonian Tropical Research Institute.
For the rest of the 20th century, SI maintained its high standing in the advancement of science under the direction of scientist-secretaries. SI science expanded rapidly in the 1960s and 1970s, when ample funds were available for equipment, expeditions, and collection management. Those favorable circumstances attracted world-class scientists to the Institution. In 1965, Secretary S. Dillon Ripley established the newest of the federally supported science units, the Chesapeake Bay Center for Environmental Studies, now known as the Smithsonian Environmental Research Center, for the conduct of natural history and ecological research. As universities became less interested in whole-organism study, the Smithsonian, with