In 1897, a major reorganization occurred in the USNM. At that time, three new departments--Anthropology, Biology, and Geology--were created to oversee the work of the museum. Former USNM departments became divisions of the new departments. This scheme of organization remained fairly constant for the next 60 years. In 1919, the Department of Arts and Industries (after 1938, the Department of Engineering and Industries) was established and assumed responsibility for collections related to mechanical technology, mineral technology, textiles, medical sciences, graphic arts, and photography. The Department of Biology was separated into Departments of Zoology and Botany in 1947, and in 1948, an independent Department of History was established.

In 1957, two administrative subdivisions were created under the direction of the USNM: the Museum of Natural History (the former USNM Departments of Anthropology, Botany, Geology, and Zoology) and the Museum of History and Technology (the former USNM Departments of Engineering and Industries and History). By 1967, the USNM as an administrative entity ceased to exist, and the Museum of Natural History and the Museum of History and Technology became separate administrative units.

Spencer F. Baird was appointed Assistant Secretary of the Smithsonian Institution in 1850, with primary responsibility for the direction of the National Museum. The title "Assistant Secretary" was not reserved for the administrator of the museum; and throughout the history of the Institution there have been officials known as Assistant Secretaries who had other duties. During the 1940s the title, Assistant Secretary was permanently attached to other duties, and the responsibility for the museum fell to an official known as Director, United States National Museum.

Incumbents included Spencer F. Baird, 1850-1881; G. Brown Goode, 1881-1896, including the years 1881-1887 when he served as Assistant Director of the Museum without the title of Assistant Secretary; Charles D. Walcott, Acting Assistant Secretary, 1897-1898; Richard Rathbun, 1897-1918; William de Chastignier Ravenel, 1918-1925, with the title Administrative Assistant to the Secretary, in charge of the USNM; Alexander Wetmore, 1925-1948; Remington Kellogg, Director, USNM, 1948-1962; and Frank A. Taylor, Director, USNM, 1962-1967.

In 1931, the position of Associate Director, USNM, was established to assume many of the administrative and budgetary responsibilities of the Museum. John Enos Graf was appointed to the post. When Graf was promoted to Assistant Secretary of the Smithsonian Institution in 1945, the position of Associate Director, USNM, was not continued.

Revised: August 28, 2002