Trained at Göttingen, the mathematician Hans Rademacher was expelled by the Nazis from his position at the University of Breslau in 1934 due to his pacifist beliefs. Settling at the University of Pennsylvania, Rademacher is bet known for his contributions in number theory. The Rademacher Collection consists of several manuscripts by Rademacher pertaining to modular forms and analytical number theory. Among these are an important unpublished work, Über ein spezielles orthogonalsystem, which had been believed lost until rediscovered by Emil Grosswald, the manuscript for a published article on Ramanujan identities under modular substitution, extensive notes for a lecture on Dedekind sums, and a book-length manuscript on analytical number theory.

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 These papers include personal and professional correspondence, manuscripts of both published and unpublished works, and memorabilia.