Stanton was the eighth of 11 children. She was born to Margaret Livingston and Daniel Cady, a respected lawyer, judge, and congressman. As a precocious child, she spent much of her girlhood observing the goings-on at her father’s law office, where she was disgusted to learn of the many inequitable laws restricting women’s freedom and ability to inherit property. She even schemed to snip the offending passages out of her father’s law books in the hope of changing them. While he would later disapprove of her activism, Judge Cady initially encouraged his daughter by loaning her law books and explaining that objectionable statutes could be overturned by public appeals to the government. “Thus was the future object of my life foreshadowed and my duty plainly outlined,” Stanton later wrote.

In 1839, Elizabeth Cady met and fell in love with an abolitionist lecturer and journalist named Henry Stanton. The two were married a year later—Elizabeth insisted on having the word “obey” removed from their wedding vows—and went on to settle in Boston, where they became active in the anti-slavery cause and rubbed elbows with the likes of Frederick Douglass and William Lloyd Garrison. Along with providing a blueprint for her later social activism, Stanton’s experiences in the abolitionist movement helped spark her involvement in women’s rights. A key incident came at the 1840 World Anti-Slavery Convention in London, where women delegates were unfairly excluded from the proceedings and banished to a visitors’ gallery. Stung by the hypocrisy of their male counterparts, Stanton and fellow abolitionist Lucretia Mott resolved to begin a political crusade on behalf of their gender. They would remain allies until Mott’s death in 1880.

While living in Seneca Falls, New York in 1848, Stanton joined with Lucretia Mott and others in convening 300 people for a convention “to discuss the social, civil and religious conditions and rights of Woman.” Stanton took center stage with a reading of her “Declaration of Sentiments,” a rewriting of the Declaration of Independence that proclaimed, “We hold these truths to be self-evident: that all men and women are created equal.” The document was accompanied by a series of resolutions to be ratified by those in attendance. Much to the chagrin of her fellow organizers, who feared they would be ridiculed, Stanton insisted on including a measure supporting women’s right to vote. The resolution passed after considerable debate, forever changing the direction of the movement and establishing Stanton as one of the most provocative thinkers on the subject of women’s rights.

Stanton gave birth to seven children between 1842 and 1859, but while she continued to write from the confines of her home, her duties as a wife and mother often prevented her from taking an active role in the women’s rights movement. The self-described “caged lioness” finally found a vehicle for her philosophy in 1851, when she met the Massachusetts-born Quaker and reformer Susan B. Anthony. The two women struck up a lifelong friendship, and the unmarried Anthony later traveled the country delivering speeches that Stanton had composed in between bathing her kids and cooking meals. Anthony sometimes even babysat the Stanton brood to give her friend time to work. Stanton returned to the road after her children were grown, but Anthony continued to serve as the face of the women’s rights movement for the rest of their lives. “I forged the thunderbolts and she fired them,” Stanton later said.

Though barred from voting, Stanton knew there was no law preventing her from taking national office if elected. With this in mind, she announced in 1866 that she was running for a Congressional seat in New York. “I have no political antecedents to recommend me to your support,” she wrote in a letter announcing her candidacy, “but my creed is free speech, free press, free men, and free trade—the cardinal points of democracy.” Stanton went on to receive a total of 24 votes—some of the first ever cast for a female politician.

In her later years, Stanton fought for women’s rights alongside her youngest daughter, Harriot Stanton Blatch. A graduate of Vassar College, Harriot joined the struggle in the 1880s and later assisted her mother and Susan B. Anthony in completing their multi-volume “History of Woman Suffrage.” After Stanton’s death, she founded the Equality League of Self-Supporting Women, an organization that enlisted thousands of low-income factory and garment workers into the suffrage movement. The group played a key role in finally securing passage of the 19th Amendment in 1919, and Harriot went on to join reformer Alice Paul and others in lobbying for an additional Equal Rights Amendment. Concerned that Stanton’s contributions to the cause were being forgotten, she later collaborated with her brother Theodore on a 1922 book about their mother’s life and legacy.