At a time when Rio de Janeiro celebrated the centenary of Brazilian Independence and São Paulo staged its “Week of Modern Art” (1922), the subúrbios were likewise presented as spaces for the “conquest of civilization.” Their development was framed both by hygienist thinking, which sought to improve the national “race,” and by the emerging vocabulary of urban planning. Disseminated through the press, this discourse primarily served the interests of land developers eager to increase the value of their properties.

By comparing newspaper articles advocating the “suburban cause” with the actual evolution of the built environment—through urban plans and the growing number of crime and local-news reports—the chapter demonstrates that these peripheral districts, far from erasing the social contrasts denounced by hygienists, reproduced them. Around railway stations emerged cortiços (tenement housing) and zones of social relegation.

Drawing on urban morphology, the chapter identifies social groups distributed across space. The comparison reveals a greater degree of complexity in Rio de Janeiro, where a long-established urban culture blurred racial categories. Many residents of Madureira occupied intermediate social positions, and color labels such as preto and pardo functioned in the press less as descriptive categories than as forms of social disqualification. In São Paulo, by contrast, the polarizations between Italians and Black people inherited from the plantation system were reproduced.

This still fluid socio-spatial organization would become more clearly defined with the new waves of population growth that arrived in the late 1920s.