The centerpiece of downtown is the monumental Empire-style City Hall, which occupies an entire block in the center of the city. According to Wikipedia, the building and was constructed from 1871 until 1901 at a cost of $24 million. It was designed by Scottish-born architect John McArthur, Jr. in the ornate Second Empire style. With almost 700 rooms, it is the largest municipal building in the United States and possibly one of the largest in the world.
This is a circa. 1899 photograph from the Library of Congress Prints and Photographs Division, Washington, D.C. (online here).
Here is some of the architectural detail and statuary. The latter two photographs I took from my room in the Marriott Courtyard Philadelphia Downtown hotel. It would be hard to find a more convenient location.
The tower is quite an edifice, but unfortunately its impressive size is somewhat diminished by the tall office buildings nearby. The antenna spire is 548 ft up, and Wikipedia claims that from 1901 to 1908, this was the tallest habitable building in the world (the distinction is in contrast to religious buildings like cathedrals and monuments like the Eiffel tower). William Penn is on the top, and he is 11-m tall and faces northeast.
According to the Wikipedia article, in the 1950s, city fathers considered demolishing the city hall, but the cost would have been too high. I do not doubt this story; the 1950s may have been the low period in the American consciousness pertaining to historical preservation. Recall this was the era when the so-called "modern" interstates were slashed across cities, often chopping up historic ethnic neighborhoods. Suburbia and white flight reigned supreme during this period, and inner cities were left to deteriorate and fester. See Building Suburbia, Green Fields and Urban Growth, 1820-2000 by Dolores Hayden for more details of the suburban flight and its consequences to American cities. Philadelphia's revived downtown shows that many people are finally returning to traditional cities, although the McMansion orgy of the 1990s-mid-2000s demonstrates a recent and gross extreme of the suburban flight trend.
Photographs taken with a Fujifilm F31fd digital compact camera.