Even though many early computer programmers in the mid-twentieth century were women, American women faced (and continue to face) prejudice in the fields of mathematics and computer science. Two examples of women in these fields within Manuscript Division collections include pioneer computer programmer Klára Dán von Neumann (1911-1963) and mathematician Betty Shannon (1922-2017). Von Neumann's papers (19,100 items; 1912-2000; bulk 1935-1963) include materials associated with her scientific career; her extensive correspondence with spouse John von Neumann concerning professional and family matters; and her correspondence with physicists, mathematicians, fellow programmers, and members of her family. Betty Shannon was mathematician Claude Shannon’s primary collaborator. Evidence of their collaboration can be found within the Claude Shannon papers (7,000 items; 1932-1995; bulk 1938-1989).