American astronomer and educator, founder of the science of dendrochronology. Associated with the Harvard College Observatory, 1889-1894, and its expedition to Peru; as well as the Lowell Observatories in Flagstaff, Arizona, 1894-1901, and Mexico, 1896-1897. At the University of Arizona, Tucson, 1906-1962; Douglass served as professor, dean, acting president, and first director of the Laboratory of Tree-Ring Research, and also the Steward Observatory.

Chiefly materials related to A.E. Douglass' astronomical and tree-ring research, and administration, at the Harvard College Observatory, Lowell Observatories, Steward Observatory, Laboratory of Tree-Ring Research, and University of Arizona. Includes correspondence, photographs, and an unpublished biography.