A gifted mathematician, Polish-born Stanislaw Ulam made contributions to set theory, topology, mathematical logic, and number theory, but is most widely remembered for his work in fostering the technical development of thermonuclear weapons. He was associated with Los Alamos Scientific Laboratories for most of the years between 1943 and 1965, and thereafter with the University of Colorado. These papers include personal and professional correspondence, manuscripts of both published and unpublished works, and memorabilia.

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.