Forty years ago today, in a city that gay New Yorkers would find unrecognizable, teenaged “sissy boys” confronted New York City’s riot police in a running battle through the streets of Greenwich Village. As one long-dead observer noted: “The cops looked like someone who’d been bitten by a trusted pet — a look of astonishment and fear at the same time.”

For the police, the late-night raid on the Stonewall Inn — a mafia-run gay bar and dance club on Christopher Street off Sheridan Square — was routine and by the book: Round up patrons. Check ID. Check anatomy. Arrest transvestites and anyone else who didn’t pass muster. Impound liquor. Take cash register. Padlock front door and call it a night. Wait a few days and repeat. Things had played out exactly this way countless times before at gay bars across the city, even earlier that same week in a previous raid at the Stonewall.

But this time it was the police who wound up in lockup, hiding behind the hastily barricaded front door of the Stonewall trying to fend off a seething crowd of bar patrons, onlookers and gay street kids who’d had enough. Enough police raids. Enough arrests. Enough humiliation. Enough!

First the coins flew (“You came for your payoff, now here’s some more!”), then the bricks, and then a parking meter battering ram. Before the confrontation ran its course, a potent symbol of the gay civil rights movement had been born. Gay people, who had almost always submitted quietly, fought back against police repression. And not just that night, but for several more sweaty and contentious nights in the sweltering summer of 1969.

Whole books have been written about what happened at the Stonewall Inn, none more definitive and comprehensive than David Carter’s “Stonewall.” What emerges from Carter’s account contradicts the customary beliefs about Stonewall. Rock-throwing transvestites didn’t start the fight (cross-dressing was against the law so it was rare to find anyone in full drag). It was a butch lesbian resisting arrest who likely triggered the melee. And leading the charge against the police were the street kids — mostly teenaged boys, homeless and feminine in ways that made them untouchable to their families. They were the ones who had the least to lose and whose identities are recalled in made up noms de guerre: Jackie Hormona, Zazu Nova, Marsha P. Johnson, and Birdie Rivera.

While the Stonewall melee proved to be a key pivot point in gay rights history, it did not mark the start of the gay civil rights movement. That came 19 years earlier in Los Angeles, when eight gay men (including fashion designer Rudi Gernreich) gathered in secret to found the Mattachine Society, an organization dedicated to bringing about change for the nation’s oppressed homosexuals — a wildly radical idea for the times.

Stonewall also wasn’t a riot of epic proportions, however tempting it is to imagine it as such. In truth, it was nothing like the fierce and deadly riots that had rocked cities and charred urban neighborhoods around the county in 1967 and 1968 — not even close. The uprising wasn’t even the first time that gay people had confronted the police. In San Francisco in 1965, for example, there was a huge and well-documented confrontation with police at a New Year’s Day costume ball. That battle quickly launched new, more activist gay rights organizations that fought to bring about dramatic changes in how that city dealt with its gay citizens.

Despite the mythic status of Stonewall as a transformational event — one now marked by annual parades and celebrations around the world — gay people across the country were not immediately inspired by what happened on Christopher Street. Most never even heard about it. Even if they had, they would have been crazy to join the fight. The price of going public — coming out — and joining the still fledgling gay civil rights movement was potentially very high. Exposure in 1969 could cost you your job, your family, and even your apartment. It wasn’t until 1973 that homosexuality was even removed from the official list of mental illnesses. Most gay people would have told you it was only the crazy ones who dared to speak up.

Change for gay people came slowly in New York City, with bar raids and police entrapment continuing through the early 1970s despite routine confrontations between young gay activists and the city’s liberal mayor, John Lindsay. Uncertain of the political costs, Lindsay was reluctant to respond to gay demands that he put an end to officially sanctioned repression and discrimination.

Yet it was against the backdrop of this intolerance that Stonewall became a romantic myth — the cinematic idea of high-kicking transvestites in full drag and stiletto heels facing off against jack-booted storm troopers.

Stonewall, which over time has become a shorthand symbol of gay pride and an inspiration to carry on the fight in communities across the country, was in the end no revolution. It was an unexpected and modestly bloody confrontation that quickened the pace of an evolution — one that’s been hard fought, often fractious, and by comparison to other civil rights efforts, remarkably swift.

So what has made Stonewall such a potent and appealing symbol to gay men and lesbians everywhere? The simple fact that gay people, so often stereotyped and dismissed as timid and meek, fought back.

Eric Marcus is the author of “Making Gay History” and is a senior advisor on an upcoming PBS American Experience documentary about the Stonewall uprising.