In August 1973 and March 1974, tens of thousands of left-wing Peronists filled the Buenos Aires stadium where the Club Atlético Atlanta soccer team usually played. These demonstrations showed the political Left’s force during a period of escalating conflict with right-wing strains of Peronism. The urban arteries that bordered the Atlanta stadium allowed the event organizers to plan for large groups to approach from several directions. As soccer and political practices converged in a single site, the demonstrations revealed how soccer culture permeated a city and how political practices transformed the stadium into a multilayered symbol. Drawing on fliers, photographs, contemporary reports, and historical maps, this article analyzes how mapping the event with Neatline offers insight into repertoires of political and stadium cultures and demonstrates how the open-source archival platform Omeka can organize photographs and historical maps to unpack the stadium’s multiple layers of symbolism.