The paper explores mobilization to reduce the deepest inequalities in the two largest democracies, those along caste lines in India and racial lines in the United States. I compare how the groups at the bottom of these ethnic hierarchies—India's former untouchable castes (Dalits) and African Americans—mobilized from the 1940s to the 1970s in pursuit of full citizenship: the franchise, representation, civil rights, and social rights. Experiences in two regions of historically high inequality (the Kaveri and Mississippi Deltas) are compared in their national contexts. Similarities in demographic patterns, group boundaries, socioeconomic relations, regimes, and enfranchisement timing facilitate comparison. Important differences in nationalist and civic discourse, official and popular social classification, and stratification patterns influenced the two groups’ mobilizations, enfranchisement, representation, alliances, and relationships with political parties. The nation was imagined to clearly include Dalits earlier in India than to encompass African Americans in the United States. Race was the primary and bipolar official and popular identity axis in the United States, unlike caste in India. African Americans responded by emphasizing racial discourses while Dalit mobilizations foregrounded more porously bordered community visions. These different circumstances enabled more widespread African American mobilization, but offered Dalits more favorable interethnic alliances, party incorporation, and policy accommodation, particularly in historically highly unequal regions. Therefore, group representation and policy benefits increased sooner and more in India than in the United States, especially in regions of historically high group inequality such as the Kaveri and other major river Deltas relative to the Deep South, including Mississippi.