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Philadelphia as an Urban Laboratory
As the son of Jewish immigrants from Estonia, Kahn described the city of Philadelphia—where he grew up, studied architecture, and maintained his office—as a “City of Opportunities.” For Kahn as an architect, Philadelphia became a kind of laboratory where he explored the relationship between building design and city planning and developed his own urbanistic and architectural principles. 

Urban History
Philadelphia, with its downtown street grid laid out by Thomas Holme under William Penn in 1683, is the birthplace of American independence (1776). By the mid-nineteenth century, the city had become the capital of America’s machine industry and the third-largest American city (after New York City and Chicago). In 1876, Philadelphia became the host of the first World’s Fair on American soil. The opening of the Benjamin Franklin Parkway, beginning in 1917, transformed the “cradle of the nation” into one of the key sites of the American City Beautiful movement—just when Kahn became interested in architecture for the first time. 

Urban Decline
During Kahn’s lifetime, architects were confronted with the rapid decline of the inner city caused by the massive impact of the automobile and subsequent suburbanization. Under Edmund N. Bacon, Director of the City Planning Commission (1949–70), Philadelphia became a laboratory of contemporary urbanism and a model for “soft” urban renewal, guided by the notion of healing “with penicillin, not surgery.” In the process, the more pragmatic Bacon, who had been a collaborator of Kahn’s, became his adversary and prevented Kahn’s proposals from being realized. 

Urban Visions
In spite of this, Kahn played a pioneering role in thinking about urban development. Starting out with housing projects, during the 1950s and 1960s, Kahn advocated increasingly radical and visionary concepts for the reconstruction of Philadelphia’s inner city. Among his key proposals were a systematic reorganization of urban traffic (defining the inner city as a large pedestrian zone) and the bold project of the six-hundred-foot-high City Hall Tower. The projected 1976 World’s Fair in Philadelphia, which he envisioned as a “Forum of Availabilities,” never took place.