This text reassesses the history of planning ideas and the impact of the planning process in the US since 1900. It analyzes the social, political, economic, ideological, economic, bureaucratic and environmental contexts in which planning has occurred. The focus is on large and small metropolitan areas all over America, with a range of planners, issues and influences considered in order to explain how the 20th-century built environment has developed. Topics covered include parks, civic improvement, housing reform, social planning, zoning, federal urban policy, public works and historic preservation.