This chapter explores working-class residents’ daily lives, standards of living, and challenges in São Paulo between 1891 and 1918. Examining this understudied period underscores the dramatic changes World War I wrought in the city. Wartime shortages disrupted the natural ebb and flow of migration, job opportunities, and urbanization, making a difficult reality more challenging for much of the city’s working class. Some scholars have argued that the war incentivized textile production and encouraged growth, but evidence from immigrant letters and prices demonstrates increased costs for low-quality textiles. The war also cut short job opportunities and educational advancements, saw a slowdown in most standard-of-living measures, and institutionalized the family wage and informality. While city officials founded weekly food markets to assist with rising food costs, these efforts were insufficient. By 1917, the situation had deteriorated enough to provide the necessary conditions for workers, both women and men, to mobilize a general strike.