Here’s a recipe for disaster: Take a pervasive social ill, add zealous reformers who ignore human nature, mix in unbearable political pressure, and top it off with a large dollop of hypocrisy.

A century ago, that was the toxic formula that gave America Prohibition. How on earth did a nation that couldn’t get by without alcohol end up outlawing it for 14 years?

The answer can seem perplexing, but an exhibition at the Lyman Allyn Art Museum in New London explains it clearly and revealingly. “Spirited: Prohibition in America” is a concise walk through the entire, crazy phenomenon, from its 19th-century roots through 1933, when everyone came to their senses.

If there’s an overarching lesson, it may be that society should be careful what it wishes for, because Prohibition, if nothing else, proved the law of unintended consequences. It changed the country in countless ways, most of them useless for the cause of getting people to stop drinking.

Not that it wasn’t a worthy cause. The exhibition begins by detailing the outsize role of alcohol in American society all the way back to the beginning. A ship that arrived in Massachusetts in 1630, for instance, carried three times as much beer as water.

Water was part of the problem. In early America, it wasn’t always safe to drink, so whiskey and hard cider became beverages of choice. By the 19th century, alcohol abuse was so widespread that temperance groups sprang up, joining religious leaders in calling, hopelessly, for moderation.

On Christmas Eve 1873, women knelt in the snow and prayed outside 13 saloons in Hillsboro, Ohio. Within days, nine of them had closed, and a political movement was born. Groups like the Woman’s Christian Temperance Union began by crusading town by town and grew 250,000 strong as their efforts gathered steam.

But it took a different pressure group with more savvy and muscle to push an anti-alcohol agenda in Washington and get results. The Anti-Saloon League, founded in 1893, was the National Rifle Association of its day, fearsome in its single-mindedness. No other issue mattered. It was the friend of any “dry” candidate for office and the destroyer of all others.

Though Americans kept on drinking, the group’s tactics were so effective that by 1916, dry forces were a supermajority in Congress. By then, it was clear that only a constitutional amendment would achieve the dream of outlawing alcohol nationwide.

With all the right politicians in place, the daunting process of approving and ratifying an amendment, even one so improbable, was accomplished with ease. Many voted for what few actually wanted.

The story of Prohibition is complex and not easy to boil down to essentials. The exhibition, made up primarily of display boards, is heavy on text and photos, and relatively light on artifacts. It tells more than it shows, and the approach works.

Organized by the National Constitution Center in Philadelphia in partnership with the Mid-America Arts Alliance in Kansas City, Mo., the traveling exhibition was made possible by NEH on the Road, an effort by the National Endowment for the Humanities to reach smaller venues around the country.

The Lyman Allyn is also hosting a three-part lecture series on Prohibition, with still-to-come installments on May 2 and 16.

As it winds its way through several rooms, the show moves from the anti-alcohol campaign that crested with the 18th amendment to the radical transformation of the country that followed.

Probably no one alive in 1920, when the amendment took effect, had any idea what lay ahead. Believers like Carrie Nation, a hatchet-wielding smasher of saloons; Billy Sunday, a baseball player turned evangelist against inebriation; and Wayne Wheeler, the master tactician who played the politicians into voting dry, may have expected a sober, more virtuous and God-fearing country.

What they got was an earthquake. The hated saloon, a man’s refuge from wife and work, morphed into the speakeasy, where the sexes drank and danced together. Women’s hemlines rose, the better to display their legs madly kicking the Charleston.

Segregation of the races eased as well-to-do whites headed uptown to Harlem to take in black entertainment at the Cotton Club. Raucous jazz music became the soundtrack of the age, loosening the corsets of a hitherto straightlaced society.

The government was indifferent to what it had wrought, leaving law enforcement underfunded as it faced the impossible task of giving teeth to the Volstead Act. Dedicated public servants like Assistant Attorney General Mabel Walker Willebrandt, the highest-ranking woman in Washington, did their best with the odds heavily against them.

A newsreel playing on a loop shows smiling Prohibition agents landing ax blows on beer barrels and hurling bottles at brick walls, but such theatrics didn’t reflect the bigger picture.

One display ranks the effectiveness of various government agencies, and the clear winner is the Coast Guard, which had modest success stemming the tide of offshore smuggling. Much of that effort was run from New London, the headquarters of its destroyer fleet.

But the law was widely flouted, and corruption was inevitable. Pages from the Hartford Courant, adding a local flavor to the show, include a screamer headline from 1921, when the chief detective of the New Britain police was busted for rumrunning along with two of his sons.

Of all Prohibition’s surprises, two must have especially stung reformers striving for a better world.

One, a wave of lawlessness and violence washed over the nation. Organized crime, which had been limited to local fiefs controlling gambling, prostitution and drugs, spread its tentacles into distribution networks to move crates of hooch over long distances.

This culminated in a 1929 summit in Atlantic City, N.J., where the country was divided into territories by crime lords like Lucky Luciano and Al Capone.

Two, people drank like crazy. They drank at home, in speakeasies and even in government offices. They drank everything from fine Canadian imports to poisonous bathtub gin that left thousands blind, paralyzed or dead.

After a decade, it was obvious to most that the country had made a terrible mistake, but there seemed no way out.

“There is as much chance of repealing the 18th amendment as there is for a hummingbird to fly to the planet Mars with the Washington Monument tied to its tail,” the amendment’s sponsor said in 1930.

Then another crisis brought salvation. The Great Depression starved the government of money as tax revenue dried up. Lawmakers began to think about the departed tax on alcohol, once its chief source of income.

Franklin Roosevelt endorsed ending Prohibition in his 1932 campaign for president, and the writing was on the wall. In short order, the country did what was widely thought impossible: repeal an amendment with another amendment.

The exhibition makes no attempt to draw parallels between Prohibition’s unexpected trajectory and current events, but they aren’t hard to imagine. Two decades ago, for example, well-meaning doctors started to overprescribe opioid pain medications, and now look where we are.

Maybe the best takeaway from Prohibition is simply this: We can solve today’s problems, but that doesn’t mean tomorrow will look the way we want it to.

j.ruddy@theday.com

If you go

What: "Spirited: Prohibition in America"

Where: Lyman Allyn Art Museum, 625 Williams St., New London

When: Through May 25

Hours: 10 a.m.-5 p.m. Tuesday-Saturday, 1-5 p.m. Sunday

Admission: $10

Information: lymanallyn.org, (860) 443-2545