Blending social, intellectual, legal, medical, gender, and cultural history, Segregation's Science: Eugenics and Society in Virginia examines how eugenic theory and practice bolstered Virginia's various cultures of segregation--rich from poor, sick from well, able from disabled, male from female, and black from white and Native American. Famously articulated by Thomas Jefferson, ideas about biological inequalities among groups evolved throughout the nineteenth century. By the early twentieth century, proponents of eugenics--the "science" of racial improvement--melded evolutionary biology and incipient genetics with long-standing cultural racism. The resulting theories, taught to generations of Virginia high school, college, and medical students, became social policy as Virginia legislators passed eugenic marriage and sterilization statutes. The enforcement of these laws victimized men and women labeled "feebleminded," African Americans, and Native Americans for over forty years. However, this is much more than the story of majority agents dominating minority subjects. Although white elites were the first to champion eugenics, by the 1910s African American Virginians were advancing their own hereditarian ideas, creating an effective counter-narrative to white scientific racism. Ultimately, segregation's science contained the seeds of biological determinism's undoing, realized through the civil, women's, Native American, and welfare rights movements. Of interest to historians, educators, biologists, physicians, and social workers, this study reminds readers that science is socially constructed; the syllogism "Science is objective; objective things are moral; therefore science is moral" remains as potentially dangerous and misleading today as it was in the past.