On the surface, it was just another tea party—a well-behaved group of women passing cups of brewed beverages around the genteel table of Jane Hunt, a well-to-do New York woman who had invited four others to dine with her.

But this tea party was not for shrinking violets. Hunt’s guests were about to air their grievances about the world’s injustices toward women—and to give birth to the convention on women’s rights that resulted in the formation of the American women’s movement.

The fateful meal took place on July 9, 1848, when Jane Hunt invited Elizabeth Cady Stanton to her house for tea. Hunt was a Quaker, and she invited three other Quakers—Lucretia Mott and her sister, Martha Wright, and Mary Ann McClintock—to the gathering, too. All five women started the afternoon as individuals. But by the end of the day, they were at the helm of a collective movement that would change women’s lives forever.

Stanton had known Mott for eight years, and the first time they met was not in a quiet gathering of women, but a rowdy group of men committed to ending slavery worldwide. Both women were ardent abolitionists, and Mott had traveled to London for the World Anti-Slavery Convention as an official American delegate. (Stanton was there on her honeymoon with her husband, an ardent abolitionist. But when they arrived, they learned that many delegates didn’t want women to attend. They were told they’d have to sit in a roped-off gallery and that they couldn’t speak or vote.)

Neither woman went without a fight, and they were joined by several of the movement’s more influential men. But in the end, they were forced to sit on the sidelines, humiliated and furious. “As Mrs. Mott and I walked home arm in arm, commenting, on the incidents of the day,” Stanton recalled, “we resolved to hold a convention as soon as we returned home, and to form a society to advocate the rights of women.”

Stanton had spent years caring for a sickly husband and three children (she’d eventually have seven), and felt lonely and isolated in Seneca Falls, where she’d moved in an attempt to help her husband’s health. She felt exhausted and exasperated by the endless, unappreciated toil her society expected of women.

Mott and Stanton had never gotten a chance to sit down together, though, until Hunt hosted them for tea. As soon as they did, the discontentment of their lives boiled over.

Meanwhile, her Quaker friends were frustrated by what they saw as the Quaker faith’s unwillingness to engage with important social issues like the abolition of slavery and women’s rights. A few months before, they had walked out of their church’s annual meeting and helped establish a new, more progressive branch of the Quaker movement. Their new group, the Congregational or Progressive Friends, allowed women and men to worship together.

As Stanton and her friends talked, they began to home in on the issues that made their lives so hard to bear. Women couldn’t get an education or vote; whether they were married or single, their livelihoods and property all belonged to the men in their lives. They felt chained by a moral code that expected women to be flawless examples and submissive wives and mothers without giving them anything in return.

“I poured out, that day, the torrent of my long-accumulating discontent,” Stanton later recalled. Her “vehemence and indignation” was met with sympathy and similar stories from her friends. They kept returning to what they’d considered before: a convention to advocate for women’s rights.

It’s unclear who decided to actually move forward with their idea; the Hunt family always held that a grandfather who felt that “faith without works is dead” encouraged them to pursue it.; Stanton wrote that all of the women resolved to “do and dare anything” after she poured out her frustrations. Either way, they decided to move forward—and quickly. Before long, they were writing an advertisement to appear in the local paper. It encouraged women and men to gather in Seneca Falls just 10 days later for “a Convention to discuss the social, civil and religious condition and rights of women.”

It may have been hastily planned, but the Seneca Falls convention would draw hundreds of attendees and be remembered as the spark that kindled the American women’s movement. Few of the women had any public-speaking experience—women were discouraged and often completely barred from speaking in public—and the women were uncertain how to organize a convention.

Despite their inexperience, they drafted an agenda and an organizing document, the Declaration of Sentiments, that would galvanize American women. Together, Hunt and her guests envisioned an equality that would smash the sexist norms of their day—and they did it with cups of tea in hand.