It's the type of building the modernists rebelled against, but unless you have a heavy emotional investment in the International Style, it's a wonder of its kind. I think it's a welcome reminder of a time when Americans felt public buildings were worth time, money, and their top designers.
Almost every possible surface is covered with allegorical statues, recreated classical garlands and columns, or just general decoration.
There are statues all around the building, including the monument below to President McKinley, who was assasinated by the anarchist Leon Czolgosz. Presumably that's why the monument refers to him as a martyr, but even given the shock of assasination I don't think he really qualifies in that category.
The naked prepubescent boy being protected/guided/inspired by the woman in the breastplate sort of amused me as being very typical of the art of its day and something that would never be done for a similar statue today, unless some daring artist wanted to create a scandal.
One of the arches features a fairly bug-eyed portrait of Ben Franklin; though an admirable man and the patron saint of the city, his is not really a countenance formed for neo-classical sculpture (which is part of his appeal).