This dissertation examines the historical and political relationship between U.S. Spanish-language radio and its Spanish-speaking listenership throughout the twentieth century. I investigate Spanish-language radio's unique institutional development, programming traits, and audience reception during specific historical instances. I employ a range of multidisciplinary methodologies---archival, policy review, ethnographic, focus groups, and discourse analysis---to construct a cultural history of Spanish-language programming that focuses on the West coast of the United States. Specifically, I argue that a Mexican-dominant listenership---largely characterized by a legacy of Spanish and U.S. colonialism, a history of proletarianism, and linguisti...