Forming a core of civic, commercial, and residential life since Philadelphia’s seventeenth-century founding, Center City has been a continually evolving experiment in urban living and management. The roughly rectangular area of about 2.3 square miles between the Delaware and Schuylkill Rivers, from Vine Street to South Street, occupies the territory of the original 1682 city plan for Philadelphia.

Surveyor Thomas Holme and founder William Penn conceived the idea for a gridded city punctuated by garden squares in the 1680s. They drew inspiration from baroque town planning, post-Great London fire (1666) concerns for city health, desires to compensate initial investors in Pennsylvania with land, and personal preferences of Penn and early interest groups such as the Free Society of Traders. The plan drawn by Holme intended settlement to occur on both the Schuylkill and Delaware waterfronts and along the main streets of High (later Market) and Broad. 

Early settlement focused on the Delaware waterfront, which became the main site of commercial and residential building and growth during the colonial era. While property at the city plan’s western edge, on the Schuylkill, remained relatively open with scattered farms and industrial workshops, the Delaware riverfront grew with wharves, warehouses, churches, taverns, and houses. Settlement hugged the Delaware shore in a semi-crescent shape, most densely along High Street and thinning to the north and south. More and more residents clustered into the area by subdividing lots. Residences of the most prosperous Philadelphians faced the main streets while smaller houses on back alleys and courts filled with laborers and the poor.

After the first printing of the plan in 1683, the river-to-river grid appeared prominently on maps of Pennsylvania, but creating a city in the image of Penn and Holme’s plan required nearly two centuries of clearing trees, leveling land, extending streets, and building upon the grid. The settled area of the city extended to Seventh Street by 1790, and by 1800 the forest had been cleared from river to river.

Adapted from the new book The Greater Philadelphia Region, Vol. 1, A New History for the Twenty-First Century (University of Pennsylvania Press): “Center City,” by Catharine Dann Roeber and Charlene Mires.

Photo features map, drawn by surveyor Thomas Holme and published in London in 1683, is the original plan for Philadelphia. William Penn hoped that development would occur along both the Schuylkill and Delaware River waterfronts and High (Market) Street, leaving plenty of open space. (Historical Society of Pennsylvania).