These records chiefly document the policy and administration of the Smithsonian under Charles G. Abbot, 1928-1944, though they overlap parts of the administrations of Secretaries Walcott and Wetmore.

Smithsonian bureaus which were founded, enlarged, or significantly changed during these years, and which are represented here, include the Smithsonian Astrophysical Observatory; the National Gallery of Art, now the National Museum of American Art; the National Gallery of Art, founded by Andrew Mellon; the National Zoological Park; the National Air Museum, now the National Air and Space Museum; and the Canal Zone Biological Area, now the Smithsonian Tropical Research Institute. Abbot's tenure was complicated by the Depression and World War II, which restricted many of the developments which seemed so promising under his predecessor. The principal event of his administration was Andrew Mellon's gift of a national art museum. Abbot created a Division of Radiation and Organisms within the Astrophysical Observatory, always his personal interest. With the use of Works Progress Administration funds he was also able to produce major improvements for the National Zoological Park. The Smithsonian continued its ties with the National Academy of Sciences, the Carnegie Institution, the National Advisory Committee for Aeronautics, the National Research Council, the National Geographic Society and similar organizations. During the war, the Smithsonian was instrumental in operating the Ethnogeographic Board and co-operated with the Office of Scientific Research and Development. Its co-operation with such bodies, and new ones like the Atomic Energy Commission, continued in the postwar years. Miscellaneous topics in the records include: the Johnson-Smithsonian Deep-Sea Expedition to the Puerto Rico Trench, 1933; the Eighth American Scientific Conference, Washington, 1940; the Smithsonian Scientific Series; North American Wildflowers; the Langley-Wright controversy; the River Basin Surveys; the abortive design competition for a museum of modern art, won by Eliel Saarinen; THE WORLD IS YOURS radio broadcasts; Robert H. Goddard's rocket research; awarding of the Langley Medal; private funding of the Smithsonian, especially the Tamblyn and Brown conferences and the 1927 conference on the future of the Smithsonian; and Charles G. Abbot's research in solar radiation and climatic studies.