Scranton, 1916 - Toronto, 2006 Disclosing scientific , theoretical urbanism and political and social activist, his most influential work was Death and Life of Great American Cities (1961 ) , in which he harshly criticized the practices of urban renewal in the fifties U.S. , whose planners assumed ideal schematic models that led to the destruction of public space. With innovative and interdisciplinary scientific methods , Jacobs identified the causes of violence in everyday urban life , as was subject to abandonment or , on the contrary , security and quality of life .

In parallel, the author noted for his activism in organizing self-defined social movements as spontaneous ( grassroots ) , designed to paralyze the development projects he understood destroying local communities. First in the U.S., where the cancellation of Lower Manhattan Expressway got ; and later in Canada, where he emigrated in 1968 and where the cancellation of Spadina Expressway and the motorway network that sought got built .