Chapter 1 introduces the study with a vignette of a critical case from Yungay, Santiago. There, a group of residents with no prior background in activism, in a city with unsympathetic political institutions and leadership, organized and achieved remarkable and sustained policy impact and stopped planned redevelopment in their neighborhood. The chapter then presents the key questions: How have citizens adapted resistance against urban redevelopment to profound political, social, and technological changes? And under what conditions do they reach their goals? The chapter justifies the focus on struggles against urban redevelopment: Urban redevelopment plays a critical role in contemporary capitalism and has important social and political implications. Investigating the struggles against redevelopment, in turn, can lead to broader insights about contentious politics. Finally, the chapter presents an overview of argument and a plan for the rest of the book.