In the mid-19th century, American cities underwent intense physical change at a pace seldom seen before or since. In Boston, reform-minded citizens tallied the costs of unrestrained change and searched for ways to control growth and create a sense of stability in their city. Their preservationist efforts helped to pioneer new approaches to planning and real estate development that eventually spread from Boston and other key cities to the rest of the nation. This is a chronicle of the relationship between historic preservation, planning, and the desire for permanence in Boston during the years from 1860 to 1930. Michael Holleran concludes that the tools invented for stopping change proved even more powerful for shaping change. New York City drew on Boston's experience to create the first comprehensive zoning ordinance which, by the end of the 1920s, had fundamentally altered the city-building process. As preservationists, environmentalists, and planners today discover common ground, says Holleran, they are in effect rediscovering the shared origins of their separate movements. This history of preservation, real estate development, city planning, and Boston's urban development should appeal to readers curious to learn more about how and why America's cities came to look the way they do.