The aim of the eugenics movement in the United States during the first half of the twentieth century was to prevent the degeneration of the white race. A central tactic of the movement was the involuntary sterilization of people labeled as feebleminded. An analysis of the practice of eugenic sterilization provides insight into how the concepts of gender, race, class, and dislability are fundamentally intertwined. I argue that in the early twentieth century, the concept of feeblemindedness came to operate as (...) an umbrella concept that linked off-white ethnicity, poverty, and gendered conceptions of lack of moral character together and that feeblemindedness thus understood functioned as the signifier of tainted whiteness. (shrink)