What Was Prohibition?

Prohibition started on January 17th 1920 in the United States of America. This was when the Eighteenth Amendment was put into action, banning the sale, manufacture, and transportation of alcohol. It lasted until 1933 when the Twenty-First Amendment repealed it — thirteen years that transformed American organised crime forever.

What Was the Eighteenth Amendment?

The Eighteenth Amendment to the US Constitution, ratified on January 16th 1919 and taking effect one year later, prohibited the manufacture, sale, and transportation of intoxicating liquors within the United States. It did not — crucially — prohibit the consumption of alcohol or its private possession, a loophole that shaped how Prohibition played out in practice.

The enforcement mechanism was the Volstead Act, passed in October 1919, which defined “intoxicating liquor” as anything containing more than 0.5% alcohol and set out the penalties for violations. A total of 1,520 Federal Prohibition agents were given the task of enforcing the law across the entire country — a hopelessly inadequate number for a nation of 100 million people.

Why Was Prohibition Introduced?

The temperance movement had been building in the United States for decades before Prohibition became law. Its driving forces were religious organisations, particularly Protestant churches, who viewed alcohol as a moral evil destroying American family life. The Anti-Saloon League, founded in 1893, became the most powerful single-issue lobby group in American political history and was the primary force behind the amendment’s passage.

The First World War also played a role — anti-German sentiment made it easier to attack the brewing industry, which was dominated by German-American families. Prohibitionists argued that grain used for brewing should go toward feeding troops, and that saloons were centres of un-American behaviour.

How Prohibition Created the American Mafia

The single most consequential effect of Prohibition was the creation of a multi-billion dollar black market that only organised crime could supply. Within months of the amendment taking effect, criminal entrepreneurs recognised the opportunity. Arnold Rothstein — already the most sophisticated criminal mind in New York — was among the first to see it clearly. He financed bootlegging operations on an industrial scale, establishing the financial and logistical infrastructure that others would copy.

Al Capone built his Chicago empire almost entirely on bootlegging revenue. At his peak in the late 1920s, Capone’s organisation was generating an estimated $60 million a year — the equivalent of over $1 billion today — from the sale of illegal alcohol. Lucky Luciano, Meyer Lansky, Bugsy Siegel, Frank Costello and virtually every major mob figure of the 20th century built their initial wealth and criminal networks during Prohibition.

The violence that accompanied the bootlegging wars — most notoriously the St Valentine’s Day Massacre of 1929 — was the direct result of competing criminal organisations fighting over territory in a market that could not be regulated through legitimate means.

Speakeasies: The Scale of Non-Compliance

Prohibition was perhaps the most widely violated law in American history. By 1925, in New York City alone, there were an estimated 30,000 to 100,000 speakeasy clubs — illegal bars operating openly with the knowledge and often the active cooperation of corrupt police officers and politicians. Frank Costello made his reputation and his fortune supplying slot machines to speakeasies across the northeast. The corruption Prohibition generated reached into every level of government, from beat cops to judges to senators.

Home brewing and moonshining also exploded. The production of industrial alcohol — permitted for legitimate purposes — was frequently diverted and adulterated for sale as drinking liquor. Deaths from poisoned alcohol were common throughout the era, as criminal producers cut their product with toxic substitutes.

The End of Prohibition

By the early 1930s, the failures of Prohibition were impossible to ignore. Crime had increased rather than decreased. Corruption was rampant. The Great Depression had made the tax revenue that alcohol could generate look attractive to a government desperately short of funds. Franklin D. Roosevelt made repeal a central plank of his 1932 presidential campaign.

The Twenty-First Amendment, ratified on December 5th 1933, repealed the Eighteenth — the only time in American history that a constitutional amendment has been repealed. Prohibition was over, but its legacy was not. The criminal organisations it had created and enriched did not dissolve when alcohol became legal again. They pivoted — into gambling, labour racketeering, narcotics and legitimate business — and the American Mafia that Prohibition had built would dominate organised crime for the next half century.

Prohibition’s Legacy

Thirteen years of Prohibition left a permanent mark on American society. It demonstrated that criminalising a widely desired product creates markets that only criminals can serve, generating enormous profits for those willing to operate outside the law. It established the organisational structures, the corruption networks, and the political connections that the American Mafia would draw on for decades after repeal. And it produced some of the most iconic figures in criminal history — men whose names remain famous nearly a century later precisely because Prohibition made them rich and powerful enough to matter.