British sleeping sickness control in colonial Uganda and Tanzania became a powerful mechanism for environmental and social engineering that defined and delineated African landscapes, reordered African mobility and access to resources. As colonialism shifted from conquest to occupation, colonial scientists exercised much influence during periods of administrative uncertainty about the role and future of colonial rule. Impartial and objective science helped to justify the British civilizing mission in East Africa by muting the moral ambiguities and violence of colonial occupation....