Michael Bronski wasn’t at Stonewall and doesn’t mind admitting it, unlike many members of the gay and lesbian community of a certain age who, he says, insist they were.

The joke is that if everyone who claims they took part in the famous 1969 uprising in lower Manhattan that catalyzed America’s gay-rights movement actually had been there, the crowd, Bronski says with a laugh, “would have filled Yankee Stadium.”

In truth, the crowd that day numbered about 200, at least at first. And they weren’t protesters but mostly patrons of the Stonewall Inn, a popular Greenwich Village gay bar.

The trouble started when the police arrived in the wee hours of June 28 to raid the Mafia-run tavern on a trumped-up liquor-license charge. Officers started pushing customers and workers into police vehicles.

But instead of dispersing as they had during past routine raids, those who hadn’t been grabbed began cheering those who had.

The crowd of onlookers swelled as tourists and neighborhood residents stopped to investigate.

Then, according to multiple accounts, a lesbian who was fighting attempts to haul her into a squad car cried out,

“Why don’t you guys do something!” The air grew thick with chants — along with bottles and bricks. The officers barricaded themselves in the bar and radioed for back-up as a riot flared.

More violent demonstrations shook the neighborhood in the following days.

Today, Bronski, a Harvard professor of the practice in media and activism in Studies of Women, Gender, and Sexuality, understands why so many claim to have been present at such a pivotal moment in the history of the gay rights movement.

“It really is like the shot heard around the world, or the hairpin drop heard round the world,” he said, a cheeky parody coined in Stonewall’s aftermath of the stanza from “Concord Hymn.”

There had been previous riots in the U.S. involving gays and lesbians fed up with routine harassment, but Stonewall, erupting when it did amid protests over the Vietnam War and civil rights and gender equality,

marked a decisive break from the more passive sexual-orientation politics of the day, said Bronski, who has written extensively on LGBTQ culture and history.