This project will investigate the historical roots of the "puebladas", a particular form of collective action that emerged in several Argentine cities during the late 1960s and early 1970s, and has recently returned to the forefront of Argenitne social and political struggle. My aim is to understand the sources, meanings, and form, i.e. the dynamics of contention, at the base of these novel form of protest, and to show how global economic change intersected with institutional processes, regional dynamics and local urban networks through the process of mass mobilization, political radicalization, and identity transformation. I will pursue this goal through and in-depth and comparative analysis of three of these insurrections: "el Tucumanazo" of 1970, "el Rocazo" of 1972, and "el Trelewaso" of 1972. My main argument is that "puebladas" worked as fields of polarization that bridged mass mobilization with political radicalization as they expanded a process of identity transformation that altered the traditional terms of Argentine political struggle, centered, since 1945, in the opposition Peronism versus Aantiperonism. For the particular case of Argentina, this study challenges simple and linear narrative that portray the radicalization of the late 1960s and early 1970s as limited to a specific set of actors and direcly leading to the militarization of politics and the establishment of state terrorism in 1976. In theoretical terms, my approach to "puebladas" displaces the study of collective action from actors, movements, and identities to forms and dynamics of struggles. Following this path, my dissertation will engage in the ongoing dialogues betwen Latin American Social Studies and renewed theories of collective action and popular politics.