An unattractive tale, but there you are. Each city chooses its heroes and Chicago has never thought to assume a prettified image for outsiders. This insistence on doing things its own way was the cause of its loss of face in 1968, so cathartic that next week's Democratic National Convention will be the first for 28 years in the city which is proud of having hosted more such events than any other.
In 1968, Richard Daley had been mayor for 13 years and Chicago had won the reputation of the City that Works. Yes, its industrial base was dwindling. Yes, there was croneyism and influence-peddling: you had to know the right people - and to have voted for them - to get your mother a decent apartment. But the streets were clean and comparatively safe, the buses ran on time and major national corporations liked being based there.
That year, hosting the Democratic convention was a poisoned chalice. Lyndon Johnson, hopelessly embroiled in the quagmire of Vietnam, had decided not to seek re-election, but anti-war activists were going to make their voices heard anyway. Demonstrators gathered and Daley's police, determined to show the nation that you couldn't do that kind of thing in the City that Works, turned on them brutally. Television viewers across the nation saw shaming pictures of blood in Lincoln Park. Traffic stopped and delegates were besieged in the convention centre. The subsequent long and ludicrous conspiracy trial of the Chicago Seven - Abbie Hoffman and the Yippies - only made matters worse.
So the Democrats stayed away through the Seventies and Eighties, and Chicago pretended that its civic pride had not been not wounded. Defiantly, it elected Mayor Daley for two more terms and today another Richard Daley, his son, rules over City Hall: croneyism may be less overt, but a good name still helps. The mayor's younger brother, Bill Daley, is co-chair of the committee that has been raising private funds for next week's convention. He brushes off the 1968 debacle as a product of its time: "It was a traumatic year, with the assassination of Martin Luther King and Robert Kennedy, student riots in Paris and the Russian invasion of Czechoslovakia. There was a real sea-change in how society looked at itself. We aren't as paranoid about 1968 as some people outside are. We're more concerned with promoting Chicago in 1996, a great city with a strong economy - and marvellous architecture."
No city is prouder of its buildings, nor has a better right to be. Its citizens can reel off the names of the currently fashionable architects and their work as fluently as Hollywood folk can recite those of film stars and directors. It has kept more of its historic centre than most American cities have managed, and the shore of Lake Michigan provides a magnificent framework to view the soaring skyline, a happy blend of the old and new.
The Chicago Architecture Foundation offers a variety of half-day walking tours embracing the bulky early skyscrapers of the turn of the century, or the slender modern masterpieces of more recent years. A popular boat ride along the Chicago River, bisecting the downtown area, provides informed commentary on major works from all eras.
Being close to the middle of America, Chicago was less exposed to outside cultural influences than the cities of the east and west coasts, and this is reflected in its buildings. Those of the 19th century show less of the Beaux-Arts adornment so beloved by the architects of New York. That fashion did not hit Chicago until the World's Fair of 1893, which manifested it to excess: but even then it did not last long. For the most part, Chicago's buildings are plainer than those of other cities and more expressive of their structure: either the heavy brick buttresses, 6ft thick and more, that held up the early skyscrapers, or the wide expanses of glass - known as Chicago windows - introduced when buildings could be supported on steel or iron frames.
Later Art Deco came to Chicago, and its best expression is in the 1930 Board of Trade building in the heart of the financial district, topped by a 31ft statue of Ceres, the Roman goddess of the abundant harvest. Take the lift the 12th floor to see the extraordinary atrium, built as part of the major 1982 extension and designed so that the old exterior wall, with its Deco detailing, now forms one side of the atrium, with glass on the other three sides. Symbolic of the thriving downtown area, the building combines the attributes that Bill Daley stresses as characterising today's Chicago: the architecture and the economy.
For what goes on inside the Board of Trade is just as intriguing as how it looks. Chicago pioneered the futures market, today one of the growth areas of international finance. What began as a means by which Midwestern grain farmers could protect themselves against fluctuating prices has grown into a sophisticated (well, fairly sophisticated) way of taking a punt on the movement of the financial and commodity markets, foreign exchange rates and much else.
You can watch it all happening from a visitors' gallery with plenty of explanatory material, including a short video. The traders operate from circles of desks and computer screens known as pits, each devoted to a single commodity, and wear bright blazers of many colours so they can be instantly recognised.
Try to be there at 9.30 in the morning, when the microphones are first switched on and a frenzied uproar marks the beginning of the day's trading. The atmosphere is like the betting ring at Aintree just before the start of the Grand National. Al Capone would have felt at home with the prevailing ethic both here and on the equally frenetic trading floor at the Chicago Mercantile Exchange a few blocks away, where a different range of futures are traded. Admission to both is free.
After that excitement, back to some quiet architecture. Frank Lloyd Wright was probably the most influential American architect in the first half of the 20th century and a marvellous collection of 25 of his houses - including the one he lived and worked in for 20 years - can be seen at Oak Park, a half-hour ride from downtown Chicago on the elevated railway. Born in Wisconsin in 1867, Lloyd Wright went to Chicago when he was 19 and worked for a while with another redoubtable architect, Louis Sullivan, whose marvellous department store for Carson Pirie Scott, in the downtown area, is a city landmark.
Moving to Oak Park in 1889, Lloyd Wright opened his own practice there four years later and became an exponent of the Prairie Style, which sought to create a distinctively American architecture inspired by the wide open spaces of the Midwest. He won commissions for many houses in this select suburb, and seen together, they provide a fascinating account of how his style developed. Few are open to the public, but there are daily guided tours of his former home, where you can hire a tape that will take you on a walking tour outside the other houses in the neighbourhood, as well as his remarkable Unity Temple.
Back downtown, Chicago evenings are alive with jazz and blues. Louis Armstrong made his name here (in Al Capone's speakeasies, among other places), and there are dozens of clubs where blues - a distinctive mixture of jazz and soul - can be enjoyed. At most of them you pay a small admission charge, then find a seat and buy as few or as many drinks as you like while you enjoy the music.
The clubs all used to be in the black quarter of town on the south side and one of the largest and most famous, Buddy Guy's Legends, is still located there, on South Wabash Avenue. Visitors will though find much more accessible clubs in the district known as River North, just north of downtown: Blue Chicago, on North Clark Street, is one.
River North is the liveliest part of the town in the evenings. Apart from the numerous jazz and blues clubs, many of the fashionable eating places are here. They range from the traditional Chicago steak house, Gene and Georgetti, on North Franklin Street, to the familiar international theme chains Planet Hollywood, the Hard Rock Cafe and "the original rock-and-roll McDonald's".
If I were to choose one quintessentially Chicago place to eat, it would be Ed Debevic's, also in River North on North Wells Street. This is a reconstructed 1950s diner that serves fairly standard hamburger-style food but is notorious for the up-front, in-your-face style of its waiters and waitresses. For the privilege of being served, you are required to endure cheerfully some mild joshing and slick repartee. The little signs on the walls catch the spirit: "If you thought you'd made reservations, you're in the wrong place"; "We are what you eat"; "Good food, fresh service".
More than any other spot, Ed Debevic's sums up Chicago's message to Democratic convention delegates, and indeed to all its visitors: "We're glad you're back, but it's on our terms. It's you who ought to be grateful for the chance of coming to this tremendous city." Quite right. So you should be.
Michael Leapman flew to Chicago with United Vacations, which offers inclusive City Break packages from pounds 399 for two nights. Phone 0181 313 0999 for details.