In this walk through urban America, with the proper light and the right lens, stone comes to life. Here are buildings designed by the best, including Charles Bulfinch, Louis Sullivan, H.H. Richardson, Frank Loyd Wright, Ludwig Mies van der Rohe, Richard Neutra, Charles Le Corbusier, Alvar Aalto, I.M. Pei, Helmut Jahn, Michael Graves, Eric Owen Moss, and Frank O. Gehry.