[2] The original routing of the tracks curved around the foundations of the ornate City Hall building above, but was rebuilt into a straightened alignment in the mid-1930s in an effort to improve travel time.

[7] In November 2011, the Central Philadelphia Development Corporation awarded construction contracts totaling $50 million for the restoration of Dilworth Park above the station, following the eviction of the Occupy Philly protesters occupying the area; this contract includes the accessibility improvements for the station.

[10] The total cost of the project rose to $55 million, with most of it coming from a federal grant, and the rest from additional contributions by the City of Philadelphia and non-profit organizations, including the William Penn Foundation.

The project was originally scheduled to have been completed July 2014, but was delayed due stairways, duct banks, and pipes encountered by construction crews that did not appear in any blueprints.

[12] In 2013, the passage of PA Act 89 (Transportation Funding Law) has allowed SEPTA to move forward with the $147 million BLT Architects-designed renovation of the 15th Street/City Hall station complex.

[18] Only the City Hall station on the Broad Street Line can be accessed inside fare control.