The Rookery illustrates a point Samuelson makes about the life cycle of Chicago's commercial buildings. The period of greatest jeopardy comes 20 to 30 years after they're first finished. At this point, a building is likely to be showing signs of age and to have gone out of fashion--think of how people feel about 1970s architecture today. Yet it's still too young for anyone to think it has historical value. Twenty years after being built, the Rookery Building looked dated and was less attractive to tenants than newer construction in the vicinity. But instead of demolishing it, the owners hired Frank Lloyd Wright to redesign the lobby. Wright's 1907 renovation squares off John Root's ornamental ironwork with marble sheeting.

The great visionary and intellect of Chicago's first wave was Wright's teacher Louis Sullivan, who wanted to bring what he called "vertical continuity" to the skyscraper--to make it look tall instead of squat. Sullivan is remembered for his aphorism, "Form follows function," which sounds odd in light of his lavishly ornamented buildings in Chicago, such as the Auditorium Theater (1885-89) and the Carson Pirie Scott department store (1899-1903).

Sullivan described ornament as "perfume"--something that helped to create the experience of a building. Only when you compare Sullivan's intricate ornament to the excesses of his late-Victorian contemporaries--the nonbearing columns, plaster deities, and gratuitous filigree--can you appreciate what a radical he was. The greatest act of vandalism Chicago committed against its architectural heritage was tearing down Sullivan's Chicago Stock Exchange Building in 1972, something Samuelson fought unsuccessfully to prevent. Even today, Chicago lacks a strong preservationist ethos. But if it had one, it would probably have fewer buildings worth saving. The greed that destroyed Sullivan's stock exchange and many other great buildings in Chicago was the same force that raised them in the first place, often on the sites of earlier masterpieces. In Chicago, they love to build and love to tear down. New York, which now considers every middle-aged building a landmark, creates fewer new ones.