This biography of Nobel Laureate Barbara McClintock (1902-1992) places her life and work in its social, scientific and personal context. The author examines the development of Barbara McClintock’s scientific work and her influence upon individuals and upon the fields of cytogenetics and evolutionary biology in the period from 1902 to the present. The history documents years of McClintock’s notable and lauded scientific work long before she discovered and named transposable elements in the mid-1940s for which she ultimately received the Nobel Prize. The biography employs documented evidence to expose, demystify, and provide clarity for legends and misinterpretations of McClintock’s life and work.