Even more than Jacobs’s death, what forced me to confront the protean quality of today’s urbanism and the inadequacy of singular definitions grew out of research and writing a book on the twentieth century, One Nation Divisible: What America Was and What It Is Becoming, coauthored with Mark J. Stern.4 Stern and I set out to examine how the 2000 U.S. Census reflected social and economic trends during the twentieth century. We concluded that America is living through a transformation as profound as the industrial revolution—one that reshapes everything, from family to class, from race and gender to cities. Events on the ground—the trends we identified and discussed—have undermined the concepts with which we interpret public life: work, city, race, family, nationality. All of them have lost their moorings in the way life is actually lived today. Their conventional meanings lie smashed, badly in need of redefinition.
The same situation occurred during the transition from the nineteenth to the twentieth century, when an emergent industrial civilization, also based on a global economy, shattered existing ideas, producing, among other changes, a new urban form: the industrial city. “ ‘Modern industry,’ is almost equivalent to ‘city life,’ ” observed University of Chicago sociologist Charles Henderson in 1909, “because the great industry, the factory system, builds cities around the chimneys of steam engines and electric plants.”5 The emergence of this new urban form—the industrial city—energized late nineteenth and early twentieth-century social science and reform. With their focus on applied research, social scientists in both Europe and the United States tried to figure out how to respond to the problems of housing, poverty, public health, employment, and governance posed by this new entity, which they understood only imperfectly. Others, such as Max Weber and Georg Simmel, searched for its essence as they advanced new theories of the city. In the United States, the attempt to define the industrial city culminated in the work of the Chicago School, which based its model on the interaction of industrial change, immigration, and social geography.6 Geographer Peirce Lewis calls this urban form, described “in any sixth-grade geography book written before the [Second World] war” as the “nucleated city”:
The railroad station was the gateway to the city, and the land with the highest value clustered nearby—occupied, quite naturally, by high-bidding commercial establishments. There the biggest cities built skyscrapers, visible monuments to the high value of center-city land. Industries located near the railroad track because it was the most eco nomical place to receive raw materials and ship out finished products. Poor people lived in disagreeable areas near the edge of the commercial district, or, more commonly, close to their place of industrial employment, often under squalid circumstances in the shadow of belching chimneys. With the help of trolley cars, affluent people moved to the outer edges of the city, or, if they could afford it, to a nearby suburb. But even suburbanites had to live near railroad stations, and even the most affluent suburbs were necessarily fairly compact.7
This nucleated city and its compact suburbs no longer exist. What has taken their place?
My point that we need new answers to the question “What is an American city?” is hardly original. Poke around just a little in current writing about cities, and it pops up, either explicitly or by implication. A keen observer, in fact, could find the dissolution of conventional urban form described much earlier than the closing decades of the twentieth century. In his monumental 1961 jeremiad, The City in History, Lewis Mumford asked, “What is the shape of the city and how does it define itself? The original container has completely disappeared: the sharp division between city and country no longer exists.”8 In the same year (which is also, remarkably, the same year Jacobs’s Death and Life was published), geographer Jean Gottman used the term Megalopolis, the title of his massive book, to describe the “almost continuous stretch of urban and suburban areas from southern New Hampshire to northern Virginia and from the Atlantic shore to the Appalachian foothills.” Within this territory, the “old distinctions between rural and urban” did not apply any longer. As a result, within Megalopolis, “we must abandon the idea of the city as a tightly settled and organized unit in which people, activities, and riches are crowded into a very small area clearly separated from its non-urban surroundings.” Although Megalopolis was most developed in the northeastern United States, it represented the future of the world.9 More recently, in his iconoclastic history of sprawl, urbanist Robert Bruegmann observed:
In the affluent industrialized world since the economic upturn of the 1970s a great many cities have been turned inside out in certain respects as the traditional commercial and industrial functions of the central city have been decanted to the edges while the central city and close-in neighborhoods have come to be home to an increasingly affluent residential population and a high-end service economy. With the penetration of urban functions into the country side, the old distinctions between urban, suburban, and rural have collapsed.10
Pronouncements by authorities are one way to illustrate the need to redefine what “city” means in the early twenty-first century. Another emerges clearly from contrasting actual cities. Philadelphia and Los Angeles provide especially apt comparisons because they embody the old and the new urban America.
A Tale of Two Cities
In 1900, Philadelphia typified urban America.11 The ecology of America’s third-largest city was a classic example of the urban ecology codified by the Chicago School of sociologists—concentric zones based on class and economic function, dotted by pockets of ethnic and racial concentration, radiating out from a central city—or of Peirce’s “nucleated city.” With its diversified manufacturing base, Philadelphia was an industrial power-house. By 2000, Philadelphia had slipped from second- to fifth-largest American city, while Los Angeles had skyrocketed from thirty-sixth to second. At the start of the twenty-first century, Los Angeles defined American urbanization. In The Next Los Angeles, Robert Gottlieb and his colleagues observe, “To understand the future of America, one needs to understand Los Angeles. Nearly every trend that is currently transforming the United States . . . has appeared in some form in Los Angeles.”12 This new megalopolis was shaped by the automobile rather than the railroad, which, along with the streetcar, had done so much to define America’s industrial cities in the nineteenth and early twentieth centuries. Los Angeles’s heterogeneous population—far more diverse than Philadelphia’s ever was—had arrived from around the globe as well as from all over America. Los Angeles’s sprawling, multicentered, multiethnic regional development stood in dramatic contrast to the old, single, dense core surrounded by residential zones and a suburban periphery, exemplified by the Philadelphia region. Even though service industries dominated its economy to an unprecedented degree, Los Angeles probably was America’s most important twentieth-century industrial city. At midcentury, its aerospace industry replaced Pennsylvania’s shipbuilders as the heart of the military-industrial complex,