This article queries how booksellers appropriated the Parisian space, at a time of profound changes. It seeks to understand the issues regarding displacements and/or the implanting of storekeepers, within the capital and sometimes outside, in terms of commercial dynamics and socio-occupational stratifications on the one hand, and trajectories and interdependent relationships on the other hand. In light of the analysis, the city emerges as the medium for and the means of revealing the upward or downward mobility of its actors, while the book is a privileged observatory of the social and urban transformations of the nineteenth century.