This article investigates the effect of political unification on population growth in Italian municipalities (comuni), during the aftermath of its unification.  During the nineteenth century, the Italian peninsula went from being a region mostly dominated by France and the Austro-Hungarian Empire, to an almost completely-unified state in 1861, and fully unified in 1871.  This article investigates the effect of this drastic political shift on the spatial distribution of population growth, considered a proxy for economic growth, at the local level.  We show that proximity to a removed border is, on average, associated with a moderate increase in population growth (about one percentage point). This average result masks important heterogeneities. First, there can be asymmetric effects on each side of a same border.  Second, the effects are not identical across all borders. For those who believe that the past can inform us about the present, the rapid political unification of Italy is also a crucial comparison point for the European Union, which has aimed at consolidating an integrated European market through political efforts. Our research sheds light on the remarkable heterogeneity in the effects of unification, at least in the short-term.