This chapter focuses on the ideology of Dominicanization in the postgenocide period. It explains the state’s project to erase the ethnic Haitian cultural, economic, and demographic presence after 1937–1938. This project to root out the Haitian presence involved surveillance and forced relocation. The regime espoused an ideal of Hispanidad that denied the Haitian and African presence in the country. Dominicanization involved the regime’s vision for both the economic and cultural development of the border provinces. The chapter explores official correspondence to consider the politicization of language, foodways, construction methods, religious practices, as well as such symbolic material embodiments of modernity as radios, billiard tables, and zinc roofing. The chapter also highlights civilian resistance and the maintenance of old border lifeways. New levels of draconian control over culture and economic activity could not fully eradicate illegal crossing, smuggling, agricultural relations, and kinship. Though Trujillo’s government demonstrated that it had the power to kill large groups of people, it did not have the power to fully control large areas of rugged territory. The aspects of border society that Trujillo’s officials considered obstacles to their Dominicanization campaign help to both reconstruct aspects of the pre-1937 border society and further explain the 1937 Genocide.