Joseph Henry's Letter to Spencer Fullerton Baird (August 16, 1862), August 16, 1862, Smithsonian Archives - History Div, Letter from Joseph Henry, first Secretary of the Smithsonian Institution, to Spencer Fullerton Baird, then Assistant Secretary and later second Secretary of the Smithsonian Institution, August 16, 1862. In the letter, Henry discusses the arrangement of shelves and cases in the Main Hall of the Smithsonian Institution Building, or "Castle," where the United States National Museum's collection was displayed at that time. The collection would be moved to the United States National Museum Building, now the Arts and Industries Building, upon its completion in 1881..