THE ENGLISH traveler James Bryce described Chicago in 1888 as "perhaps the most typically American place in America." So many people have echoed this comment over the past century that it has become virtually a cliche -- and yet a cliche with a kernel of truth at its heart.

More than any other city, Chicago's early destiny was rooted in American frontier expansion. Its growth was fueled by the process that brought the West into the orbit of a capitalist economy. Even more importantly, by concentrating the energies of the new nation into a single powerful market, it provided one of the crucial engines that enabled the 19th-century United States to expand as quickly as it did. Far from being what the historian Frederick Jackson Turner saw as the end product of the American frontier, it helped make frontier expansion possible in the first place.

Chicago thus rose to greatness as the representative "new city" of the 19th century. Just as Manchester had served as an emblem for the early industrial revolution in England, just as Los Angeles would symbolize the sprawling freeways and endless suburbias of the 20th century, Chicago seemed to many visitors the single most compelling icon of the railroads and industrial technologies that so transformed the landscape of America. On a site that had been little more than a marshy prairie as recently as 1830, an extraordinary new city exploded to become one of the world's great metropolises in less than half a century. For Americans and foreigners alike, it symbolized much that was best and worst about the young nation.

There had in fact never been anything quite like it. By 1860, Chicago was shipping more wheat, more corn, more lumber, more pork, more beef, than any other city on the planet. This tide of commodities was delivered to the city's warehouses and factories by the world's most extensive network of rail lines. As eastern capitalists and politicians invested vast sums of money and subsidies to construct the emerging transportation network, they created a new artificial geography to supplement and sometimes even replace the old network of canals, rivers and roads.

The new geography brought corn from Iowa, cattle from Texas, white pine from Michigan and workers from every corner of the globe: a cornucopia flooding Chicago's depots with people and the wealth of nature. Here, surely, was evidence that the United States was destined to be Nature's Nation, a country so favored with natural wealth that it would far surpass the older civilizations of Europe that lacked its rich endowments. Brash and raw it might be, but Chicago stood for the greatness of America's future and the abundance of its resources. Few worried about how quickly those resources might be consumed or what might happen when they ran out.

More than nature was involved, of course. No other technology in the history of civilization has had a more centralizing effect than the railroad. In the 19th century, geography, economic competition, and rate structures all conspired to funnel people and goods through a handful of cities that became exchange points for the entire system. As movement concentrated in these places, the activity of their markets, the value of their real estate, the number of their jobs and the wealth of their richest inhabitants exploded.

Virtually all large American cities expanded as a result, but Chicago enjoyed special benefits because its growth coincided with the advent of agricultural settlement on the fertile soils of the Middle West and the extension of railroads to the Plains, the Rockies and the Pacific Coast. Its markets rose to dominance just as the tall-grass prairie was being plowed under to produce wheat and corn, just as the great north woods were being cut to supply lumber and fuel for frontier farms and towns, just as the great bison herds were being slaughtered to make way for the Texas longhorns that succeeded them.

No matter where one lived in the trans-Mississippi West, chances were good that the nearest pair of rails disappeared toward an eastern horizon beyond which lay the great transportation hub on the shore of Lake Michigan. The magic of the railroad meant that, for a time at least, the entire West paid tribute to Chicago. Both Chicago and the West were forever transformed as a result.

And so the very things that made Chicago seem so extraordinary -- its sudden growth, its rawness and the monstrous scale of its enterprise -- were also what made it so exemplary of the nation and era that produced it. Although the city was itself in the shadow of the still mightier metropolis at the mouth of the Hudson River, Chicago somehow seemed more emblematic of the American heartland. This remained true even long after its original gateway role had receded. As the journalist John Gunther wrote in 1947, "New York is bigger and more spectacular and can outmatch {Chicago} in other superlatives, but it is a world' city, more European in some respects than American."

Chicago eventually lost its status as gateway to the Great West as railroads declined relative to aircraft, automobiles and diesel trucks. It remains a great manufacturing and wholesaling center, but many of its most important 19th-century industries vanished long ago. With the north woods cut over, the city could no longer supply the West with lumber. With highways and cheap electrical refrigeration making it ever easier for small western meatpacking plants to compete with their older and more crowded rival, the Union Stockyards declined and finally closed in the decades following World War II. Grain that might once have passed through the city's elevators eventually traveled by other routes -- though its price has continued to be set in the trading pits of the Chicago Board of Trade. The disembodied hinterlands of the virtual marketplace have long outlasted the physical hinterlands of an earlier era.

We no longer live in a railroad age, so perhaps this great railroad metropolis on the shore of Lake Michigan is no longer so typical as it once was. Today we read the story of its lost western empire with more ambivalence than our 19th-century predecessors. Where they saw a glorious metropolis and a rural civilization emerging from a savage wilderness, we remember the world that was lost in the process: the tall-grass prairies, the great white pines of the northern forests, the Plains bison herds and the Indian peoples whose livelihood depended on them. And yet, ironically, we are far less likely than earlier Americans to recognize the myriad ways in which a great city like this continues to remain dependent upon the rural landscapes from which it sprang. What was second nature to them has become for us a landscape in which city and country, civilization and wilderness, stand in stark opposition to one another.

That is why I still recommend the Board of Trade, looming at the foot of La Salle Street, as one of the most important tourist destinations for any visitor seeking to understand not just Chicago, but the United States and modernity in general. Watching the frenzied actions of the traders as they speculate in wheat futures, soybeans and all manner of options and financial instruments, one sees a maelstrom of pure market activity, the swirling heart of modern capitalism. It is a compelling icon of the unseen engines on which we unknowingly depend to sustain our modern lives.

But what one also sees at the Board is an artifact of the ghost hinterlands, the vanished natural ecosystems and rural landscapes, that were forever transformed by this city and its markets. Standing in the tourist galleries and watching the futures market in action, one can ponder the paradox it poses. At few places on earth can we witness more nakedly our connections with the people and creatures of remote places on which our lives utterly depend . . . and yet at few places are we more struck by how little we understand those connections.

Just so do the ghost hinterlands of Chicago's past continue to haunt our common future. Just so does Chicago continue to stand as a symbol for much more than just itself. Just so does it remain a most compellingly typical place. William Cronon, the author of "Nature's Metropolis: Chicago and the Great West," teaches at the University of Wisconsin. CAPTION:Where modern Chicago began: The county courthouse and the downtown business district after the Great Fire of 1871. CAPTION: Where modern Chicago began: The county courthouse and the downtown business district after the Great Fire of 1871.