For many years, Las Vegas' success as a honeypot for sin-seekers made up for the lack of other trades. But now America's landscape for decadence has expanded beyond this desert oasis, Kevin Connolly finds the city needs a new selling point.
If the South of France is a sunny place for shady people, then Las Vegas, Nevada, is a bright place where dark desires flourish.
The city blazes its neon promise of wealth without work against the inky darkness of the desert sky so vividly, it is said to be visible from space.
Now, speaking as an American taxpayer, I hope astronauts have something more useful to occupy them than verifying dubious urban myths about the visibility from orbit of the Vegas skyline, or indeed the Great Wall of China.
But anyway, Vegas is synonymous with the doomed optimism of gambling.
Indeed, it owes its very existence to the way in which hope can flourish where despair would come rather easily to hand.
If you couldn't shoot craps or buy yourself a beer in the small hours of Sunday morning in Oregon, you could come to Nevada and do it there
Much of Nevada has the sort of parched and hostile appearance you might achieve by bombing the surface of the moon. But Spanish explorers rather optimistically named Las Vegas - which means "The Meadows" - in celebration of the life-giving springs of water they found there as they mapped their new world.
And there is always been something a little different about Nevada.
In the middle of the 19th Century, this hot, forbidding and thinly populated territory out in the Western deserts was hurriedly granted statehood during the Civil War, to make sure the Union side would have the congressional votes it needed in the confused and divided peace that was to follow.
There was a little money to be made in mining copper and lead, but as the decades went on it became obvious that Nevada lacked resources.
For one thing, the state boundaries had been drawn around one of the few bits of the American south-west with no oil under it - and for another, Nevada is boiling hot.
Until air-conditioning made it bearable, it was inhabited in summer only by hardy frontier families and Western desperadoes.
Its solution was ingenious. In the words of one eminent American historian, it decided to treat its own sovereignty as an economic asset.
In plain English, it decided to allow things that were not allowed anywhere else - and I don't mean the over ground nuclear testing which the US government carried out there in the 1950s.
Getting married in Las Vegas is a major draw for tourists
I mean the way Nevada decided to trade in sin - and then tax it.
If you couldn't shoot craps or buy yourself a beer in the small hours of Sunday morning in Oregon or Arkansas - well, you could come to Nevada and do it there.
If other states curtailed your right to drunkenly get married in the middle of the night to someone you'd only met after you'd started drinking earlier in the evening, that became legal too.
And if it didn't work out - well, you could also get divorced more easily in Nevada than you could almost anywhere else in America.
Even prostitution is legal in some parts of Nevada. One brothel recently started advertising a male hooker for the ladies' market. He's known as a prosti-dude.
In general terms, sin has worked rather well. Las Vegas - Sin City - became rich and respectable.
Where Vegas once stood alone as an island of sin, America's landscape of decadence is now much more crowded
Gangsters dug the foundations of the city's prosperity - and indeed sometimes buried each other underneath them - but big business eventually took over.
To this day, the casino industry remains at the heart of the economy. It pays for the state education system for example - a particular irony when you consider that gambling could be considered a tax on stupidity, which relies on customers with a shaky grasp of maths.
Sadly though, sin is no longer really a unique selling point.
You can get divorced anywhere you like in America these days of course, and while it's still relatively easy to marry in Nevada, the registration bureau now shuts up shop at midnight.
Is it just me, or does that take some of the spontaneity out of drunkenly marrying a stranger?
But the biggest change of all has come in the profile of gambling in the United States - another area where the balance has shifted in recent years between the twin American impulses of Puritanism and the vigorous pursuit of happiness.
Where Vegas once stood alone as an island of sin, America's landscape of decadence is now much more crowded.
Gambling on tourism
Casinos are still in abundance for those who flock there to gamble
Atlantic City, New Jersey, for example, a clapped out resort in the early 1970s, turned to casino gambling to power its regeneration in 1976.
Then, gambling rights were granted to America's 546 federally recognised Indian tribes. Now, 43 of the 50 states have legal lotteries and 19 permit casino gaming.
American law remains oddly straight-laced about gambling over the internet as distinct from gambling in person at the roulette wheel - but Nevada no longer has a monopoly on sin.
It can hardly go back to lead-mining or over ground nuclear testing of course, and the city of Las Vegas now sees its future in a broader form of tourism. It's a resort where you can gamble, not merely a resort you visit in order to gamble.
That is a tough and competitive road of course. There are plenty of other places around the world where you can spend your tourist dollar.
Still, when you look at how this blazing city of light was constructed out of the hostile rock of the Western deserts, you really wouldn't bet against Las Vegas.
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