Two centuries ago, Paris, a city with a population of half a million, barely extended beyond its medieval footprint. São Paulo was still largely a small trading outpost for gold and exploration expeditions. And Los Angeles was just a pueblo of a few dozen buildings.
Over the next 200 years, and accelerating rapidly during the second half of the twentieth century, this would all change. Today, the Paris metropolitan area sprawls out over more than 6,600 square miles, metropolitan São Paulo over more than 3,000 square miles, and metro L.A. over nearly 4,900 square miles.
A set of three new map animations from my colleagues at NYU's Stern Urbanization Project tracks the history behind these decades of geographic expansion. The visualizations show successive booms in the physical footprints of Paris since 1800, São Paulo since 1881, and L.A. since 1877. The team will release their full research, covering the history, future, and implications of urban expansion in 30 cities, at the World Urban Forum in Medellín, Colombia, later this week.
Built from data in Shlomo Angel's Atlas of Urban Expansion, these show the quick expansion of city centers and suburbs in the late nineteenth and early twentieth century, along with the much more astoundingly rapid expansion of suburban and exurban areas in the second half of the twentieth century. During this time period, many cities saw their built area increase by a factor of more than 10.
Take Paris, the oldest city featured in the visualizations. Distant pockets began to pop up beyond the old city as early as the 1830s, and the city center itself grew following Haussmann's renovations in the 1850s and 1860s. By the 1870s, a steady stream of growth began. The city's suburbs took off again after World War II,with a suburban boom in the 1950s and 1960s and a rapid expansion of the exurbs by the 1980s and 1990s.
In São Paulo, a slow growth in the late nineteenth century led to small expansions in the early years of the twentieth. There was a boom in growth close to the city center in the 1930s, and by the 1950s the waves of red and orange signal the city's growing domination of the region.
And in Los Angeles, we can see the multiple nodes of growth that defined the sprawling region for much of the twentieth century. Growth took off first around World War II, and the city expanded west during the 1940s. During the 1970s and 1980s, the spread of orange across the landscape is a signal of the rapid sprawl that many associate with Southern California.