After the United States became a world power at the end of the Spanish-Cuban-American War of 1898, it also inaugurated its first successful overseas disease eradication efforts against yellow fever in Cuba and hookworm disease in Puerto Rico. In the 1910s, these initial campaigns were replicated in Brazil through the international health services of the Rockefeller Foundation.

This dissertation examines the consequences of these campaigns in order to understand the ways in which public health transformed the racial and national thinking of early twentieth-century Cuba, Puerto Rico, and Brazil. American and local physicians used public health concerns to bolster state building and define national belonging. In Cuba, public health officials, social scientists, and policy makers exploited the success of the yellow fever campaign to police racial boundaries, generally to the detriment of people of African and Asian descent. In Puerto Rico, the campaign against hookworm mobilized tens of thousands of peasants and offered a platform to expand medical research and training. In Brazil, the missions of nationalist sanitarians and the Rockefeller Foundation converged in the campaign of rural sanitation and altered ideas about regionalism, nationalism, and imperialism.

Furthermore, my research demonstrates that as state authorities implemented disease eradication programs, social thinkers replaced older doctrines of race and environment with less tangible explanations of soul and culture to reassess national identity in the tropics. In Cuba, Puerto Rico, and Brazil public health ideas also had a profound impact on key intellectual figures of the 1930s who redefined the national community in writings influenced by their ambiguous relationship with the United States.

My analysis draws on U.S. military records, medical journals, ethnographies, autobiographies, novels, popular images, and documents of the Rockefeller Foundation to reconstruct the circulation of public health campaigns in and among these countries. These campaigns provide a window onto the complex political and cultural dynamics that linked the histories of Cuba, Puerto Rico, and Brazil with the history of the United States. By integrating stories from the archives with intellectual history, I draw out connections between public health, immigration, cultural nationalism, and U.S. imperialism in the Americas.