This project analyzes the impact of the Carter Administration’s human rights policies in the Southern Cone of Latin America, specifically Argentina and Brazil. For over a decade historians minimized the long-term impact of the Carter years, but lately many have re-assessed their historical judgment and pointed out to the institutionalization of human rights as a major political success. The thesis tries to understand if, how and why the Carter Presidency effectively dealt with right-wing dictatorships as a watershed from previous administrations. The project endeavors to place Carter’s foreign policy within a broader historical framework that evaluates the coherence of US policies. Often at the bottom of US geostrategic priorities during the Cold War, Latin America constituted a test for the administration’s redefinition of priorities, particularly in the aftermath of the Chilean coup d’état in 1973. The project further attempts to address two questions. Firstly, how the Administration embraced and interpreted the concept of human rights. Secondly, how the latter could serve to reaffirm American influence abroad through a redefinition of its moral values, without sacrificing Cold War interests. The results indicate that, despite evident inconsistencies, which resulted partly from the difficulties of formulating a policy, partly from the Cold War context, partly from the conflict between idealists and realists, and partly from the dynamics between each military regime and the United States, the US Administration achieved significant results.