Correspondence, memoranda, speeches, lectures, writings, reports, notes, subject files, oral history, biographical material, printed matter, slides, photographs, and other papers relating to Strand's career as professor of astronomy at Northwestern University, Evanston, Ill.; scientific director of the United States Naval Observatory, Washington, D.C.; and director of the observatory's Astrometry and Astrophysics Division. Subjects include astrometry, astrometric instrumentation design, double star photography, and scientific research for the U.S. military during World War II. Correspondents include Arthur Beer, Bart J. Bok, Dirk Brouwer, William A. Fowler, W. Fricke, H.L. Giclas, Ejnar Hertzsprung, Arthur Allen Hoag, L. Houziaux, Carlos Jaschek, Gerard Peter Kuiper, Jan Hendrik Oort, Bengt Strömgren, Otto Struve, Arthur R. Upgren, Peter Van de Kamp, and the Strand family.