The sea of iron pillars holding up the PRR's elevated trackbed was replaced in the 1890s by a 10-block stone viaduct to the Schuylkill River.

This created a block-wide barrier known as The Chinese Wall, cutting the western portion of the city in half and discouraging development there.

Those stations were completed and in operation by 1933, but a number of factors, including the Great Depression which stalled the planned redevelopment, forced the railroad to continue utilizing Broad Street Station for certain types of trains (such as the Philadelphia-New York "Clockers", and steam-powered trains of the Pennsylvania-Reading Seashore Lines) for nearly two more decades.

His plan for the redevelopment of the site included three large office towers, a pedestrian mall, and an underground concourse where retail and business was to be located.

[1] The Pennsylvania Railroad wanted to sell the land off in smaller lots for piecemeal development, but Mayor Clark used his political clout to see that Bacon's plan was realized.

[3] Throughout the mid-to-late 20th century, the city's office sector began to move west into the Penn Center area, thanks to planning efforts.