Recent critiques of conventional poverty research have highlighted the need to move beyond the conceptual limitations of “neighborhood effects” models and the use of the tropes of “adaptation” or “resistance” to explain the behaviors and actions of the urban poor. We use ethnographic field observations and interviews with public–housing residents to address these limitations in the poverty literature, assess competing explanations of poor people’s agency, and provide insight into the importance of space as a mediating link between macrostructural constraints and locally situated behaviors. We theorize agency and identity as spatial phenomena—with spatial attributes and spatial influences—and examine how different spatial meanings and locations enable or constrain particular forms of social action and behavior. Our ethnographic and interview data depict several strategies by which residents “use space” to provide a measure of security and protection, to designate and avoid areas of criminality and drug activity, and to challenge or support the redevelopment of public housing. From these data we show that urban space is not a residual phenomenon in which social action occurs, but a constitutive dimension of social life that shapes life experiences, social conflict, and action.