Editing Penns Original Plan (section)

== Design Principles ==

William Penn's design for Philadelphia drew from both practical and idealistic motivations. Having witnessed the Great Fire of London in 1666, which devastated a densely built city, Penn sought to prevent similar disasters through wide streets and dispersed development. The plan's generous lots—each originally intended to include gardens and orchards—would create space between buildings that would slow fire spread and provide residents with access to nature. This combination of safety concerns and pastoral ideals shaped a city plan quite different from contemporary European cities or even other colonial settlements.<ref name="weigley">{{cite book |last=Weigley |first=Russell |title=Philadelphia: A 300-Year History |year=1982 |publisher=W.W. Norton |location=New York}}</ref>

The grid pattern reflected Enlightenment values of rationality and order. Streets running east-west were named for trees—Chestnut, Walnut, Spruce, Pine—while those running north-south received numbers. This systematic nomenclature made navigation straightforward, in contrast to the irregular street names of older cities. The plan's symmetry and regularity expressed Penn's belief that rational design could create orderly society, an idea that would influence American city planning for generations. Philadelphia's grid became the model that cities from Savannah to San Francisco would adapt to their own circumstances.<ref name="gallery"/>