This paper, published in two parts, contains an analysis of the links between the ‘agrarian question’ in the Ecuadorian Andes and the creation of a network of indigenous‐peasant organizations that became the backbone of the national indigenous movement. Based on a monographic study in the province of Cotopaxi, in Ecuador's central sierra, I explore the relations between agrarian and social change. I analyse the agrarian roots of Andean ethnic platforms at the local level, attempting to see how those processes that politicized ethnicity came about between the 1960s and the first decade of the twenty‐first century. Beginning with the redistributive results of the state‐driven agrarian reform (1964–73), the paper demonstrates that the articulation of the contemporary indigenous movement cannot be explained without an understanding of the implications that the reform process entailed and the synergies it unleashed, amongst these being an increase in the internal differentiation of the peasantry until then subject to the power of large estate owners. Throughout this process, the leaders, authentic organic intellectuals, played a fundamental role, picking up the reins of the organizations, weaving their own political discourse and becoming independent of their external allies. In a second stage, the NGOs and cooperation agencies that focused their attention on the indigenous world made organizational strengthening a banner of their work on the ground, consolidating that structural transformation. In this paper, I explore the deep roots of the agrarian system's political economy in order to come to a full understanding of the social differentiation process and the ethnicization of the peasant movement. This contributes towards the comparative reflection of other scenarios in the Andean region and, in general, of those Latin American spaces characterized by the presence of significant contingents of indigenous‐peasant populations.