American cities are not what they were a few years ago Preliminary census returns for 1990 show that, for the first time, more than half of America's population lives in metropolitan areas of a million or more people. But the changes experienced by cities go far beyond demographics. Cities look different. They have a decisively different form, structure, and appearance. And, within the framework of newly developed and redeveloped tracts of urban land, beneath the exoskeleton of new architectural styles and redesigned cityscapes, there have emerged some important new cultural, social and political dynamics. Of course, cities are constantly changing and adapting as the restless formation and reformation of the built environment responds to the dynamics of a constantly evolving economy and society. This restlessness has been particularly pronounced, however, since the mid 1970s. Epochal changes in the world economy have brought new needs, opportunities and tensions that have quickly been written into the landscapes of cities. The classic mosaic of city neighborhoods has become blurred as the distinguishing features of class, race and family status have been overscored by lifestyle and cultural preferences. Long-established neighborhoods have either fallen into decay and social disorganization or have been 'reclaimed' by members of the bourgeoning new professional middle classes. Central Business Districts (CBDs) have experienced a selective recentralization of economic activity that has brought a renaissance of urbanity, a rash of speculative building and a sudden move toward conserving selected fragments and re-creating idealized tableaux of past development. Beyond the central city, suburban strips and subdivisions have been displaced as the conventional forms of new development by exurhan corridors, office parks, business campuses, privately-planned residential communities, and outlying commercial centers big enough to be called 'edge cities.' The builtscape of these settings is characterized by packaged landscapes and by landscapes of mixed densities and unexpected juxtapositions of forms and functions. The high tide of the latest real estate and development boom (1984-1989) has left American cities with some remarkable new packages,' not least among which are private, master-planned communities that have appeared around every large metropolitan area, creating a series of artful fragments that seem likely to prefigure the postsuburban form of the fin de millénium metropolis. Unlike their distant antecedents in the Garden City and New Town movements, their provenance is almost entirely from within the private sector, their objectives being concerned less with planning and urban design as solutions to problems of urbanization than as solutions to the problem of securing profitable new niches within the urban development industry. At the same time, they are radically different in scale, layout and composition from the residential subdivisions that have characterized the past 40 years or more of metropolitan decentralization. This paper examines this phenomenon in detail, treating them as the product of the confluence of post-Fordist economics and postmodern cultural sensibilities.