By the end of 1919, more than 70 years after the first national woman’s rights convention at Seneca Falls, Congress finally passed a federal women’s suffrage amendment to the U.S. Constitution. But the fate of the 19th Amendment all came down to Tennessee.

In the summer of 1920, women’s suffragists and their opponents met in sweltering Nashville, Tennessee, for the climactic clash in a decades-long fight over the American woman’s right to vote. After a dramatic showdown in the state legislature, the Tennessee House voted by the narrowest of margins to pass the amendment on August 18.

On August 26—now celebrated as Women’s Equality Day—the 19th Amendment officially became part of the Constitution. By this time, women in New Zealand, Australia, Finland, Denmark, Norway, Canada, Austria, Germany, Poland, Russia and the Netherlands had already gained the right to vote, while 15 states around the country (particularly in the West) had changed their constitutions to give women voting rights. But the 19th Amendment changed the federal laws of the land.

By the early 19th century American women lacked not only suffrage, but many other basic rights. A married woman could not own property or sign a contract; she had no right to her wages if she worked, and she had no custodial rights to her own children.

“These women see their place in society as being oppressed," Elaine Weiss, author of The Woman’s Hour: The Great Fight to Win the Vote, says of Lucretia Mott, Elizabeth Cady Stanton and the other earliest pioneers of the women’s rights movement. Many of them were Quakers, who believed all humans had divine rights, and they began their activist careers as abolitionists, fighting for the liberation of an even more oppressed minority: slaves.

When Mott and Stanton organized the first women’s rights conference at Seneca Falls, New York in 1848, Stanton included a suffrage resolution in her now-famous Declaration of Sentiments, based on the Declaration of Independence. Though most people at the conference thought it was too radical, the resolution passed by a slim margin (in part thanks to the eloquent support of Frederick Douglass) and the demand for the vote would eventually become the central goal of the women’s rights movement.

In 1853, Stanton met fellow abolitionist Susan B. Anthony; their collaboration would last for more than a half century. After the Civil War, Anthony and Stanton split with other women’s rights advocates during the debate over the new constitutional amendments giving civil and political rights (including suffrage) to newly freed slaves.

Instead, for the first time in the entire Constitution, the proposed 14th Amendment specifically included the phrase “male citizen,” while the 15th Amendment stated that the right to vote cannot be denied on account of “race, color, or previous condition of servitude,” not mentioning sex. "They assume that after the Civil War...that universal suffrage will be implemented,” Weiss says. “And they are very severely disappointed and angered when they're told that's not going to happen."

Douglass and other abolitionists argued that the nation couldn’t handle two enormous reforms at once, and that black men needed these rights in order to survive. Unconvinced, Anthony and Stanton broke away from more moderate women’s rights activists and fought actively against passage of the 15th Amendment, even resorting to racist rhetoric in their fury over uneducated black men winning the vote before educated white women.

These two competing sides of the women’s rights movement would reunite in 1890, forming the National American Women Suffrage Association (NAWSA). But the movement split once more in the early 20th century, as some younger activists grew impatient with the slow pace of the fight for suffrage, and decided to take a more active approach. "The same splits and tensions happen in Great Britain, which is running a parallel course towards enfranchisement," Weiss points out.

Alice Paul, founder of the new Congressional Union for Woman Suffrage (later renamed the National Women’s Party), had studied with the radical Emmeline Pankhurst in Britain, while NAWSA leader Carrie Chapman Catt was close with Millicent Fawcett, leader of the more conservative British suffragist movement. But while Pankhurst’s followers planted bombs and set fires, their American counterparts were far less militant, restricting their tactics to public demonstrations like picketing and parades.

"Alice Paul is a Quaker, she doesn't believe in violence,” Weiss says. “But she does believe in open protest….She's going to make a lot of noise. She's not going to be ladylike. She's not going to ask for the vote, she's going to demand it."

Though the first women’s suffrage amendment had been introduced in Congress in 1878, it had gone effectively nowhere since then. "Every year they go up, every year they testify, every year it goes back into the file cabinet,” Weiss says, describing the growing frustration of the suffragists. “And this happened for 42 years."

Things began to change during World War I. With U.S. entry into the conflict in 1917, American women took on new roles in service of their country, replacing absent men in the workforce at home, volunteering in relief organizations and even serving in the military. “They took on what was called men's work,” Weiss says. “They risked their lives abroad, they were in the mines, in the fields, in the factories here. They proved their patriotism…So it became harder and harder politically for politicians to say women don't deserve the vote."

Meanwhile, the two sides of the suffrage movement took different approaches to pursuing their goals during wartime. Paul and her Women’s Party followers picketed outside the White House and called out President Woodrow Wilson for his lack of active support for women’s enfranchisement.

Arrested in 1917 and sentenced to seven months in jail, Paul organized a hunger strike in prison; media coverage of her treatment earned sympathy for the suffragist cause. For her part, Catt swallowed her pacifist views and convinced fellow NAWSA members to work in support of the war effort.

By 1918, Wilson had announced his support for women’s suffrage as a wartime measure, helping the amendment pass in the House of Representatives that January. The Senate followed suit in June 1919, and it went to the states for ratification.

Weiss’ book chronicles in detail the dramatic events of July and August 1920 in Nashville, when both NAWSA and the Women’s Party had their representatives working frantically to secure the state’s ratification. Also on hand was a dedicated contingent from the anti-suffrage movement, spearheaded in Tennessee by women like Josephine Pearson, president of the Tennessee State Association Opposed to Women’s Suffrage, who saw women’s suffrage as a dire threat to white supremacy and the traditional southern way of life.

“It's not just the numbers of black women,” Weiss says. “Because black men had legally had the right to vote since 1870, but the southern states had figured out how to disenfranchise black men for decades.” (They soon would do the same for black women). Instead, anti-suffragists feared that giving black women the vote would put them on an equal plane with white women.

Unfortunately, this racist mindset affected white suffragists as well, many of whom resisted embracing their black counterparts in their eagerness to get the suffrage amendment ratified in southern states. "They make the argument—well, if you give white women the vote, there are more white women than black women, so white supremacy won't be threatened by this,” Weiss says. “It's not a very commendable argument, but these are now political compromises being made.”

For many in the South, the prospect of a federal women’s suffrage amendment also brought back unwelcome memories of the Reconstruction era and passage of the 14th and 15th Amendments. In an election year, both the Democratic and Republican presidential candidates (James Cox and Warren Harding, respectively) had issued vague statements in support of suffrage, neither eager to accept responsibility or blame for the outcome in Nashville. Democratic Governor Albert Roberts, who worked to get ratification passed, would be rewarded by a defeat in his reelection campaign that November.

The heated battle over ratification in Tennessee became known as the “War of the Roses,” as suffragists and their supporters wore yellow roses and “Antis” wore red. The resolution for ratification passed relatively easily in the Tennessee Senate, but the House was bitterly divided. The final outcome, on August 18, came down to a tie-breaking reversal by Harry Burn, a young red-rose wearing representative who had received a pro-suffrage plea from his mother.

Despite the best efforts of the Antis to discredit the vote and block ratification with legal arguments, the 19th Amendment became part of the U.S. Constitution on August 26, 1920. That November, some 10 million American women—a little more than a third of all eligible female voters—headed to the polls, marking a major milestone in a battle for female equality and true universal suffrage that is not yet won.