When William Penn located his city of Philadelphia between two rivers, the Delaware and the Schuylkill, he reasoned that ships could use either river to discharge or to take on new cargo. He envisioned the City growing inward from the shores of both rivers toward Centre Square and Broad Street. This plan influenced the numbering of the north - south streets on his famous grid.
Map of improved part of Pennsylvania in America, 1681, Thomas Holme
Much land was pre-sold even before the incorporation of the City of Philadelphia in 1682.
Those buying in the City also received a piece of land in the "Liberties," or suburbs.
Higher resolution image here.
In total, twenty-three streets ran north and south covering the area from the Delaware to the Schuylkill. On the Delaware side the north - south streets began at Front Street and progressed westward to 2nd Street, 3rd Street, building in number to 13th Street where the numbering ceased at the border of Centre Square (City Hall). The next north-south street, the widest in Philadelphia, was called Broad Street. It ran up to Centre Square, stopped and picked up again on the other side.
At the Schuylkill banks, a new set of north - south streets was counted in reverse, west to east. A Front Street appeared alongside the Schuylkill River, next came 2nd Street, 3rd Street, etc., the numbers climbing as the streets proceeded east toward Broad Street. At Schuylkill 4th Street, North West Square (later, Logan Square) interrupted the north-south streets. To avoid confusion, an "S" for Schuylkill would appear before each numbered street so S Front Street or S 5th Street indicated numbered streets on the west side of Broad Street. If no "S" appeared, the street was located east of Broad Street.
​
​
Map showing location of lots as given to original purchasers or their grantees, 1680.
Streets are numbered along High (Market) Street from the Schuykill to Centre Square.
Higher resolution image here.
This peculiar repetitive numbering is mentioned in The Stranger's Guide, published by Edward Parker, Bookseller, 178 High Street, published in 1810 and in To the Citizens of Philadelphia: This new plan of the city of Philadelphia and environs taken from actual survey. Created by John A. Paxton, 1811.
This New Plan Of the City of Philadelphia and Environs, 1811, John Paxton.
On the higher resolution image here you can see the north-south street numbering. Baldwin Park would be between S 4th and S 5th Streets.
You can also see the planned but never completed canals in dark blue running east-west along the future Callowhill Cut and south along Broad Street.
​
A problem developed that William Penn had not foreseen. Ships were unable to sail very far up the Schuylkill River. The result was concentrated development at the Delaware River side. Settlement lagged near the Schuylkill River. Country estates and farms were established west of Broad Street all the way to the Schuylkill River. The area surrounding Logan Square remained untouched hardwood forest for much of the l700's. Soon the "S" disappeared and the numbering of east to west took over. S 8th Street became 15th Street.
​
Map of plan of the City from 1794 (dated 1776 on map), P.C. Varle.
You can see asymmetrical development of the City with the darker brown on the right (east) of the City representing developed land, and vacant land on the Schuylkill.
Higher resolution here.
In 1854 at the time of consolidation of City and County, the street numbering system was changed to better integrate the two square-mile City of Philadelphia with the adjoining districts. The "Schuylkill" naming system was dropped. As this diagram from 1861 shows, the blocks were given numbers based on a decimal system, addresses spanning 100 on each block, instead of running continuously from east to west. See article here.
For those Uber drivers among our readers, here is the rule for determining whether a street address is on your right of left, from The Stranger's Guide, 1810
(High Street is now Market Street)
It could have been even simpler to locate oneself if the east-west streets had been named as numbered avenues centered on Market Street instead of trees (Center City) or governors (South Philly). Arch would have been 1st Avenue North and Chestnut 1st Avenue South. Over time even the tree nomenclature was corrupted: Arch was originally Mulberry; Race was originally Sassafras; and South was originally Cedar (and still is in West Philly). Here is one mnemonic for remembering the sequence of the streets running east-west in Center City.
text authored by Sandy Owens 8/2018, with images and captions by Joe Walsh