For more than a month now, the press has been full of stories of “illegal” parties in Downing Street. The government, we are told, has almost ground to a halt because of the scandal.

Given the coverage, one might easily get the impression that the law-breaking bash is a recent invention, something that could only happen in lockdown, driven by privilege and an unhealthy sense of entitlement. Yet the modern party began life as a crime just over a century ago, when the Volstead Act banned the production and sale of alcohol in the US. As the New York Times explained in 1920:

You cannot carry a hip flask.
You cannot give away or receive a bottle of liquor as a gift.
You cannot take liquor to hotels or restaurants and drink it in the public dining rooms.
You cannot buy or sell formulas or recipes for homemade liquors.
You cannot …

It was not technically illegal to drink at home – but procuring the booze for a party meant breaking the law. Not that that stopped everyone. The first “cocktail parties”, claimed the hard-drinking writer F Scott Fitzgerald, who was at most of them, were held in 1921. By the following year the New York Times was complaining that the once-innocent word “party” now meant, by definition, an “inebriate” bash. Fitzgerald found the whole thing so intoxicating that he wrote one of the century’s defining novels, The Great Gatsby, about a bootlegger famous for his decadent parties and limitless cocktails.

Prohibition was America’s first culture war, imposing the conservative morality of teetotal small towns on cities vilified as warrens of drunken immigrants – Italians with their wine, Irish with their whiskey, Germans with their beer. Revisionist historians claim it was a success, reducing illness and crime. But that’s a narrow view of an extreme attempt to remake modern life. Prohibition changed behaviour all right – for it put wild parties at the centre of modern culture.

Cocktails, the classic lubricant of the 1920s party, may have helped hide the awful taste of bootleg spirits. Or perhaps they just got you drunk faster. Either way, the rise of cocktail parties redefined what a party was. Soon this cocktail scene had spread to Europe. Even though drinking was legal in the UK, the aristocratic Bright Young Things in 1920s England managed to give their parties a spectacular excess that outraged and entertained the onlooking, purportedly sober and dull, masses. When police deferentially but firmly tried to end a party at St George’s Baths, London, in 1928, the Bright Young guests, all boozing in their bathing costumes, tried to get the bobbies to join them in the pool. Another novelist, Evelyn Waugh, evoked the permanent drunkenness of the decade in Vile Bodies’ nauseous opening on a wave-tossed ship in the Channel:

“Oh,” said the Bright Young People. “Oh, oh, oh.”

“It’s just exactly like being inside a cocktail shaker,” said Miles Malpractice.