Indigenous peoples have been used and imagined as guardians of the Brazilian frontier since at least the mid-nineteenth century. This association was central to the foundation of the Indian Protection Service (Serviço de Proteção aos Índios, or SPI) during the early 1900s and culminated with the Amazonian Vigilance System (Sistema de Vigelância da Amazônia, or SIVAM) at the turn of the millennium. Throughout the period, the abiding desire to establish defensive dominion over disputed national territory subjected individuals and groups identified as “Indians” to the power of overlapping discourses of scientific progress, national security, and economic development. A trinity of Brazilian modernity, these goals interpellated native peoples primarily through the practice and rhetoric of education, which grounds their historical relationship with dominant national society. Drawing on SPI records, government documents, journalism, personal testimonies, and visual media, this article traces the impact of this modernist trinity on indigenist policy and in the lives of those who have been affected by its tutelary power. By transforming private indigenous spaces into public domain, Brazil's politics of anti-imperialist imperialism propagated a colonialist, metonymic relationship between “our Indians” and “our America” into the twenty-first century.