An exploration of technology and the logic of American racism. Sarah E. Chinn pulls together what seem to be opposite discourses - the information-driven languages of law and medicine and the subjective logics of racism - to examine a range of primary social case studies such as the American Red Cross's lamentable decision to segregate black blood during World War II and its ramifications for American culture, and more recent examples revealing the eugenicist roots of criminology such as the trial of O.J. Simpson. She also analyzes several key American literary texts such as Mark Twain's novel "Pudd'nhead Wilson", the plot of which turns issues of racial identity, and which was written at a time when scientific and popular interest in evidence of the body - not only in fingerprinting, but in phrenology and blood typing -was at a peak. Through her analysis of the history of science, US popular culture, sensationalized court cases, forensic technology and literary texts, the author reveals how in the United States issues of blood and skin have been manipulated to bear the evidence of racial identity during the 20th century.