Between 1900 and 1940, at least 100,000 individuals in the southern United States died of pellagra, a dietary deficiency disease. Although half of these pellagra victims were African-American and more than two-thirds were women, contemporary observers paid little attention to these gender and racial differences in their analyses of disease. This article reviews the classic epidemiological studies of Joseph Goldberger and Edgar Sydenstricker, who argued that pellagra was deeply rooted in the political economy of cotton monoculture in the South. The methods that Sydenstricker brought to epidemiology from early work on political economy obscured the role of gender inequalities in pellagra, and his focus on economic underdevelopment led him to ignore the prominent role of African-Americans as pellagra's principal victims. Research methods and traditions, no less than more overt ideologies, played a role in maintaining the subordinate social position of women and African-Americans in the southern United States.