These are the most famous, well-loved and best behaved cows that Chicago has known, which has a lot to do with the fact that they are made of fibreglass.
For months more than 300 of them stood around the city centre as ornaments, contemporary art and just plain fun, delighting the residents. "Anything that can take my teenager downtown four times must be good," said Dave Durham, as he prepared for the charity auction last night where they were to be sold off.
They are pure fantasy and imagination, some in pop art or psychedelic colours, a Mondrian, Magritte and Miro, one in red mirror tiles, and another covered with bottle tops. There are cows done up as grandes dames with dresses and pearls, a space cow in full Nasa kit called "Mooooooonwalk", a Yankee Doodle cow, one with a shark's fin, and, my favourite, a carmine red cow suspended upside down and entitled Odalisque (Reclining Nude). There is one on display in the United Airlines office, a member of the Coldstream Guards, complete with bearskin and chin strap, but all the rest have been corralled into the theatre.
For many years, Chicago was a little wary of being called Cowtown. The city has long thought of itself as a sophisticated, international metropolis, not a centre for cattle auctions any more. Today Chicago is a sophisticated international metropolis, utterly confident of itself, the centre of the city revived by a booming economy, a smart mayor and a lot of hard work. It can afford to laugh at itself a little.
It made its fortune through its vast stockyards, abattoirs and meat packing plants. Agriculture is still very important - farm machinery makers John Deere and Caterpillar and agribusiness giants such as Archer Daniels Midland are locals, and much of Illinois is still farming country.
But the giant Chicago exchanges are more likely to be trading financial futures than longhorns these days, and many of those giant buildings sprouting out in the fields are distribution centres for electronic commerce companies.
Chicagoans still have a love affair with the cow in another form, suitably aged, perfectly grilled and plonked on to a plate with some of Idaho's finest potatoes and a little freshly made English mustard. Only in Buenos Aires and Kbe in Japan will you find a similar fixation on steak.
At Gibsons, one of the finest steak houses in the world, they will lovingly show you the cuts before you order, indicating the finer points of the marbling and the texture.
There is everything from a dainty little 22-ounce (600g) ribeye to the life-threatening 48-ounce Porterhouse, which presumably requires health insurance - they sell three or four a night.
Preceded by a vase full of gin Martini, accompanied by a bottle of hefty cabernet sauvignon and followed by a cigar in the bar afterwards, this is a truly Chicagoan meal, one that leaves you with great respect for these tough, gritty Mid-westerners and their tough, gritty digestive systems.
Cows, on a plate, or as art that is frivolous, wild, wacky and endearing, have helped Chicago to crystallise a sense of itself as a city on the up. It was a typical gesture from Richard Daley, who is sometimes mocked as "Mayor of the Flowerpots" for his obsessive interest in the details of city management, but he understands intuitively what works and what makes people happy.
The cows helped Chicago to get one up on New York. As they were on display in Chicago, Mayor Rudolph Giuliani was trying to close down the "Sensation" exhibition in Brooklyn, which included two cows in 12 parts by the British artist Damien Hirst.
"While Daley is positively upbeat, Mayor Giuliani comes across as a mean man," said Thomas Cochran, executive director of the US Conference of Mayors. "It is interesting how art affects two cities and how two mayors use art - one in a very positive way and the other negative - to convey different messages." For a city with a robust sense of civic pride, it was mooooosic to their ears.