INTHE POET Carl Sandburg described the city of Chicago in the opening poem of his book Chicago Poems.

Hog Butcher for the World,
Tool Maker, Stacker of Wheat,
Player with Railroads and the Nation's Freight Handler;
Stormy, husky, brawling,
City of the Big Shoulders . . .

In these few words Sandburg captured perfectly the industry and vitality of Chicago during the early years of the twentieth century. Other American cities of the time could have been described in a similar way.

If Sandburg were to visit Chicago today, however, he would have trouble recognizing the city he knew. Much of the nation's freight now bypasses Chicago, traveling by air and trucks instead of by rail. The stockyards and packing plants that made Chicago a world leader in meat processing have all but disappeared, and many of the toolmakers have gone out of...