These documents cover the years 1847 to 1953, the year of Millikan's death, but the core of the collection consists of the official papers generated by Millikan after his move to Pasadena in 1921. The collection includes more than 125,000 pages of letters, notebooks, unpublished speeches, addresses, lecture notes, and family papers.

Primary source materials for the history of quantum physics in the twentieth century, collected under the auspices of the American Philosophical Society and the American Physical Society, with a grant from the National Science Foundation.