Jane Jacobs left New York City in 1968 and went into self-imposed exile in Canada. Yet when she died April 25 at the age of 89 in Toronto, she was remembered as one of the greatest advocates of New York City’s urbanism. While the rest of the country thought of New York as too densely developed, overcrowded, and dangerous, Jane Jacobs wrote passionately about how its density and diversity made the city livable and exciting.

In a nation that was mostly rural in 1898 when the City of New York was created, the American Dream was small town America and the big city was its nightmare. Jane Jacobs helped retire the myths of the big city.

Jacobs didn’t just wake up one morning in 1961 and write her classic book, The Death and Life of Great American Cities – today, required reading for architects, urban planners and everyone who study cities. Her ideas arose from her lived experience on Hudson Street, in Manhattan’s West Village, and from her years of active struggle to protect her neighborhood from the city’s grandiose urban renewal plans. A nemesis of Robert Moses, the city’s development czar, she saw the city’s planners call lively human-scale neighborhoods “slums” and “blighted,” then bulldoze them. They were replaced by dull high rises set in wide-open wastelands without a street life – the modernist model of the “tower in the park.” She fought and helped kill the Lower Manhattan Expressway and an urban renewal plan for her own neighborhood. Her book, released in 1961, resonated with the thousands of activists who were fighting battles against urban renewal, highways that cut through the hearts of cities, and grandiose megaprojects. Thus, her brilliant insights are best understood in their historical context, as contributions to the struggles to save neighborhoods from orthodox urban planning.

Jacobs saw incredible richness and diversity in neighborhoods that development-hungry planners disqualified as chaotic and dysfunctional. Of course, she had no financial stake in seeing her neighborhood leveled, and perhaps because of that there was a fundamental difference in the way she perceived the city. Cities aren’t just physical forms but rich landscapes for social and economic relations among people. How do people use the streets and sidewalks? How do the people who work in industries, retail customers, tenants and homeowners interact and coexist with one another? By asking these questions she came upon principles of physical planning that were embedded in the built environment. These relations, which at one point she likened to a “symphony,” and not the abstract visions of planners and developers, were for her the starting point for planning.

Jane Jacobs’ remarkable catalog of urban treasures has inspired generations of urban professionals searching for alternatives to the modernistic bombast and monumentalism that created sterile downtowns, isolated public housing, and sprawled suburban enclaves. Her work contributed to the flourishing of the neighborhood preservation movements, and influenced many other progressive New York urbanists including City Planning commissioners from Beverly Moss Spatt in the 1960s to Ron Shiffman in the 1990s, both advocates of decentralized planning involving neighborhoods. Author Roberta Gratz (The Livable City) and William Whyte, founder of Project for Public Spaces, carried forward many of her ideas. Indeed, there aren’t too many professional planners of all stripes who don’t acknowledge in some way her important contributions.

The city’s fiscal crisis in the 1970s and the federal government’s withdrawal of funds for large urban renewal and public works projects created fertile ground for Jacobs’ alternative way of seeing the city. After Robert Moses retired, government austerity left no money for ambitious public projects or for aggressive urban planners that would reincarnate the master builder. With widespread neighborhood abandonment, professionals had to search for ways to improve communities using the resources that were already there. Organizers and activists in community-based organizations, consciously or not, followed Jacobs’ approach of strengthening the human bonds in neighborhoods and building on existing assets. The city’s housing agency created neighborhood preservation programs. The city created a Landmarks Commission in 1965 that would help protect historic buildings and districts. And the City Planning Department later initiated contextual zoning to encourage new development in context with the existing built form. While all of these initiatives have their limitations, and some of them are used mostly to protect exclusive enclaves, they are part of a toolkit of measures that can be used to protect everything valuable in neighborhoods.

One area in which Jacobs’ admonitions have been mostly ignored is in planning for streets and sidewalks. She showed how mixing pedestrians, cars and bicycles and encouraging an active street life was important to livable neighborhoods. The city’s Department of Transportation, however, is mostly dedicated to moving as many vehicles as quickly as possible through streets. For the most part, the same logic applies to sidewalks. Jacobs felt that having many “eyes on the street” contributed to a lively and safe environment. That means encouraging people to move slowly, stop, talk, and “hang out,” and slowing vehicular traffic.

As happens with many great thinkers, Jane Jacobs is cited by real estate developers and planners who interpret her work in ways she might well question. For example, Alexander Garvin, influential urban planner in New York City, was quoted in the April 27 New York Times as saying The Death and Life of Great American Cities, “changed my life.” Yet Garvin’s reputation is as a pragmatic planner who tries to find better ways to accommodate new development, not community preservation. For example, he was the author of the city’s ambitious Olympics 2012 plan that created sports venues sharply disconnected from neighborhoods. Jane Jacobs on many occasions spoke up against such megaprojects in Toronto.

The New Urbanism is a recent trend in urban planning and architecture that proposes re-creating traditional, walkable communities following the model of 19th Century small-town America. But contrary to many of her critics, Jacobs wasn’t a nostalgic looking to idealize the old. The sterile New Urbanist experiments like Seaside and Celebration in Florida are a far cry from the bustling diversity that Jacobs saw in her West Village.

Jane Jacobs was hardly a traditionalist. She was truly a rebel. She dared to look lovingly and with care at her neighborhood. She stood up to the powerful Robert Moses. She criticized racial discrimination in housing and employment (for example, in her book The Economy of Cities, she cites W.E.B. DuBois and goes on to criticize the inadequacy of programs to aid minority contractors). Her family’s opposition to the war in Vietnam drove her to self-exile in Canada. And ever since then she supported progressive planning, and good hearty urban protest, throughout North America. She most recently sent a message of solidarity to community groups in Greenpoint/Williamsburg (Brooklyn) fighting the city’s massive waterfront rezoning project. Jane Jacobs was a true New Yorker.

Tom Angotti is Professor of Urban Affairs and Planning at Hunter College, City University of NY, editor of Progressive Planning Magazine, and a member of the Task Force on Community-based Planning.