Traffic on Dearborn and Randolph

Chicago has always been a logistics center. Historically overlaid networks of water, rail, highway, and air travel make today’s city a major node in the vast systems of global commerce. More than natural forces, the flow of goods and people have shaped the metropolis’s architecture and landscape. At the turn of the twentieth century the city of trade turned hypertrophic: life in Chicago's center reaching an unprecedented, even notorious, density. Later decades, however, would demonstrate that urban development is not unidirectional, but involves cycles of densification and disaggregation, of ebb and flow, over the life of the city.