Abstract: We exploit the construction and eventual demise of the colonial railroads in Ghana, and most of the rest of Africa, to study the impact of transportation investments in poor countries. Using new data on railroads and cities spanning over one century, we find that railroads had large effects on the distribution of economic activity during the colonial period and these effects have persisted to date, although railroads collapsed and road networks expanded considerably after independence. Initial transportation investments may thus have large effects in poor countries. As countries develop, increasing returns solidify their spatial distribution, and subsequent investments may have smaller effects.