Philadelphia's Street Plan: William Penn's "Greene Countrie Towne"

Philadelphia's grid is America's first planned city—laid out in 1682 by surveyor Thomas Holme under William Penn's vision of a "green country town" with light, air, and firebreaks.

The Grid

• Orthogonal: North–south (numbered) × East–west (named) — 1st to 28th (originally 12th) × Vine to South (originally Cedar).
• Wide streets: 50–100 ft rights-of-way — unprecedented in 17th-century urbanism.
• Five squares: Center (City Hall), NE (Franklin), NW (Logan), SW (Rittenhouse), SE (Washington) — public lungs.

Naming Logic

• N–S: Numbers (Front = 1st) — rational, expandable.
• E–W: Tree/plant names (Chestnut, Walnut, Locust, Spruce, Pine, Race, Vine, Market, Arch, Cherry) — nature in nomenclature.
• Exceptions: Broad Street (14th, 113 ft wide), Market Street (High St. historically), Benjamin Franklin Parkway (diagonal, City Museum corridor).

Landmarks on the Grid

• Independence Hall (Chestnut btw 5th/6th) — Declaration, Constitution.
• Liberty Bell Center (6th & Market).
• Franklin Institute (20th & Benjamin Franklin Pkwy) — science museum.
• City Hall (Center Square) — world's tallest masonry building (1901–1908), William Penn statue atop.

Legacy

The grid survived 19th-century chaos (industrial encroachment, immigration, consolidation 1854) and 20th-century highways (I-95, I-676, Vine St. Expressway). It makes Philadelphia navigable, walkable, and legible—rare for a major US city.

Penn's "greene countrie towne" became a metropolis, but the skeleton holds.