Although it strikes individuals from a variety of backgrounds, sickle cell anemia has always been known as a "black" disease in America. "In the Blood" argues that ever since the discovery in 1910 and subsequent scientific analysis of the disease, sickle cell anemia has been manipulated to serve social ends-as a tool for securing white identity and a way to establish a hierarchy based on European heritage. Tapper shows how sickle cell anemia was used to promote the superiority of racial purity, to characterize the black body as contaminated, and even to support the notion that modern humans evolved from multiple origins.