ABSTRACT In 1854, prior to the American Civil War, Gideon Lincecum (1793–1874), an enslaver and physician from Texas, proposed a law advocating for the castration of criminals to prevent additional crimes committed by men, especially Black men, and to inhibit hereditary immorality. Shockingly, Lincecum also viewed his law as a “solution” to the “immorality” of abolitionists who supported freedom for enslaved African Americans. Lincecum inspired physicians and scientists promoting eugenics in the twentieth century who racially targeted Black men as candidates for castration. Lincecum’s castration law magnifies the ugliness of scientific racism and violent perceptions of justice as deriving from the same ideological white supremacy that persisted from before the Civil War into the twentieth century.