My thesis offers the first in-depth urban cultural analysis of the network of Puerto Rican community activism in Loisaida (part of the Lower East Side) from the 1960s to the 1990s. This community organized itself to fight against postwar urban deindustrialization, housing disinvestment, and gentrification, which negatively affected low-income areas. By recreating the urban history of sustainable activism in Loisaida and focusing on the initiatives and projects of key community organizations, I demonstrate how they sought ultimately to claim specific spaces: from housing and public spaces to educational and cultural centers. The adjective 'sustainable' does not simply connote 'environmental' but rather highlights the role of the environment in a broader sense-built environment, educational environment, cultural environment-in shaping the quality of life of an urban neighborhood. Moreover, the methodologies and rhetoric of these groups frame their activism in distinctly human rights rhetoric: the right to education, the right to housing, the right to the city.