Editing Philadelphias Grid Plan (section)

== Influence and Legacy ==

Penn's grid plan for Philadelphia was among the most influential urban designs in American history. The grid layout, with its regularity, legibility, and ease of lot division, became the dominant model for American cities from the colonial era through the 19th century. When the federal government sold western lands, it used a grid system derived partly from Philadelphia's example. Cities including New York, Washington (whose diagonal avenues interrupted an underlying grid), Chicago, and countless smaller towns adopted grid plans influenced by Philadelphia's precedent. The idea that cities should be planned in advance, rather than growing organically, became a characteristically American approach to urbanism.<ref name="reps"/>

The grid has also shaped Philadelphia's development in specific ways. The regular lot sizes facilitated property development and real estate transactions. The numbered streets provided an intuitive address system that made navigation easy even for newcomers. The reserved public squares ensured that Center City would retain significant green space even as development filled every available lot. And the width of major streets like Market and Broad accommodated the increasing traffic demands of a growing city—though Penn could never have anticipated automobiles, his generous street widths proved adaptable to modern transportation. After more than 340 years, Penn's grid remains the organizing framework of Center City Philadelphia, a testament to the durability and adaptability of his visionary plan.<ref name="gallery"/>