Dilworth Park

City Hall is located in what was originally named Centre Square. Centre Square was one of the five original public squares planned by William Penn in 1682. Centre Square was the geographic heart of the city until 1854, when Philadelphia expanded its city boundaries with the Act of Consolidation. Centre Square never became the social heart of the city as originally intended, but it remained in use until 1871, when construction of City Hall began.[4]

Penn planned for Centre Square to be:

a central square or plaza of ten acres to be bordered by the principal public buildings, such as the Quaker meetinghouse, the state house, the market house, and the schoolhouse. Despite the two riverfronts [Delaware and Schuylkill, Penn's city had an inward-facing design, focusing on this central plaza.[5]

However, the Delaware riverfront would remain the de facto economic and social heart of the city for more than a century.

[…] hardly anyone lived west of Fourth Street before 1703. Consequently Penn's design of a center square as the hub of his community had to be abandoned. The large Friends meeting house which was built in 1685 at the midpoint between the rivers was dismantled in 1702. Efforts to develop the Schuylkill waterfront likewise collapsed. Of the merchants, tradesmen, and craftsmen who can be identified as living in Philadelphia around 1690, 123 lived on the Delaware side of town and only 6 on the Schuylkill side. One of the latter, a tailor named William Boulding, complained that he had invested most of his capital in his Schuylkill lot, 'so that he cannot, as others have done, Remove from the same.' Not until the mid-nineteenth century, long after the city had spilled northward and southward in an arc along the Delaware miles beyond its original limits, was the Schuylkill waterfront fully developed. Nor was Centre Square restored as the heart of Philadelphia until the construction of City Hall began in 1871.[5]