In William Penn’s original plan for Philadelphia, the streets were organized in a grid pattern, and their naming and numbering followed a specific system:
- East-West Streets (Numbered): The east-west streets were primarily numbered. Starting from the Delaware River, the first street was named Front Street, and subsequent streets moving westward were numbered sequentially (Second Street, Third Street, and so on). This numerical system made navigation relatively straightforward.
- North-South Streets (Tree Names): The north-south streets were named after trees, a reflection of Penn’s desire for a “greene country towne.” Examples include Chestnut, Walnut, Spruce, Pine, and so forth. This naming convention provided a distinct and easy-to-remember system.
- Broad and High (Market) Streets: Two major streets broke from this pattern. Broad Street ran north-south and was wider than the others, essentially bisecting the city. High Street, which later became Market Street, ran east-west and was central to the city’s commerce. These streets intersected at Centre Square, the heart of the city.
- Expansion Beyond Original Plan: As Philadelphia grew, the grid system expanded beyond Penn’s original plan. The naming and numbering system of the streets, however, largely retained its original form, contributing to a consistent and orderly expansion of the city.
This systematic approach to street naming and numbering was a significant aspect of Penn’s urban design and contributed to the city’s functionality and navigability.