In market economies such as the United States and most western nations, land-use and development patterns are influenced by government regulations and investments in infrastructure but determined largely by market forces. Under these conditions, post–World War II development patterns—when the automobile became the dominant form of transportation—became highly dispersed, haphazard, and dominated by low-density development. Scholars and planners have pejoratively characterized this as urban sprawl, to which they attribute adverse social and environmental consequences, such as high rates of farm and forest land consumption, excessive driving and resultant air pollution, costly public infrastructure, and social segmentation. For many years, efforts to combat sprawl were called “growth control” or “growth management” and primarily focused on slowing the rate of urban growth. But in the 1990s in the United States, a new term and set of ideas entered the lexicon of planners, developers, and policy makers: smart growth. Proponents of smart growth aimed to change the focus from stopping or slowing growth to assuring that growth was “smarter” in location, intensity, and form. Although the precise meaning of the term remains ambiguous, the Smart Growth Network—a national alliance of more than thirty private sector, public sector, and nongovernmental organizations—continues to advance the following ten principles: (1) mix land uses; (2) taking advantage of compact building design; (3) creating a wide range of housing opportunities and choices; (4) creating walkable neighborhoods; (5) fostering distinctive, attractive communities with a strong sense of place; (6) preserving open space, farmland, natural beauty, and critical environmental areas; (7) strengthening and directing development toward existing communities; (8) providing a variety of transportation choices; (9) making development decisions predictable, fair, and cost-effective; and (10) encouraging community and stakeholder collaboration in development decisions. Over the past twenty years, scholars have undertaken considerable research to confirm or dispute the virtues of these principles and to understand how best to implement them. Recently, smart growth advocates have begun to address more contemporary challenges, such as climate change, social equity, public health, and more. Smart growth’s underlying principles are now also represented in the popular terminologies of “sustainable development” and “urban resilience” and in broader efforts such as the United Nations 2015 Sustainable Development Goals. This article, however limited in scope to the original set of smart growth principles, traces the history of the concept and presents research that explores the validity of the principles, the challenges of implementation, and the extent of success.