The resonance between scientific theory and ideology is starkly revealed by the medical debate on slavery, alleged black inferiority, and racial differences in disease: opposing doctors invoked the same science, but relied on contrary assumptions, to reach antagonistic conclusions. Reductionist, biological determinist, and ahistorical premises underlay the dominant belief that innate racial differences led to black bondage and racial disparities in health; an anti-reductionist and historical approach supported the minority view that social factors rooted in the planters' need for cheap labor explained both. From 1830 to 1850, doctors debated the accuracy, validity, and interpretation of their findings. In the 1850s, "apolitical" doctors sought to purge medicine of politics to regain scientific objectivity, yet the first generation of black physicians argued that politics inevitably affected medical inquiry. The Civil War and Emancipation spurred studies relating the health of blacks and poor whites to social conditions, while the destruction of Reconstruction led to the resurgence of racist medicine. Comprehending how politics set the terms and tempo of this polemic can provide insight into current controversies on racial differences in disease.