From 1970 to the present, Afro-Latinx (or “Black”) movements have emerged in every country from the Rio Grande to Tierra del Fuego with an African descendant population. Black mobilization in Latin America centers on the denial of Afro-visibility and full participation in the life of the nation-state since emancipation. In a region known already for its high levels of socioeconomic inequality, Blacks and indigenous persons bear the brunt of these disparities. While Black movements are present all over the continent, Peru and Ecuador provide theoretically compelling comparisons due to the simultaneous presence of substantial indigenous mobilization. Understanding Black mobilization in the context of indigenous mobilization helps explain the distinctive features of Black mobilization because Black movements had to negotiate their claims in a political space that was predisposed to address issues of ethnic difference and less so issues of racial discrimination. This dissertation broadens the theoretical understanding of ethnic mobilization in Latin America by evaluating how existing theories of ethnic mobilization explain the mobilization of Black activists in Peru and Ecuador. My dissertation answers the following questions: 1) How did Black movements in Peru and Ecuador emerge? 2) How have they impacted the “political landscape” of their states? Investigating and theorizing the origins of the groups reveals the underlying grievances and narratives of these movements that shaped their interaction with their states. While the movements have succeeded in challenging the invisibility of Afro-descendants by their states, the broader impacts of the movements on the state (i.e., bureaucracy, electoral participation, legal regime) remain to be analyzed. Using a paired case study of the Black movements in Peru and Ecuador from 1980 to 2016, I first explain the emergence of these movements as a form of Black politics demonstrating that extant social movement formation theories can explain how the Black movements in both countries evolved. Next, I analyze the impact on the political landscape by first analyzing how movement activists articulated their demands and grievances and how the governments responded by looking at national planning documents and shifts in the national bureaucracy to create specialized agencies to address the concerns of the Black movements.