The 15th Amendment and Its Impact on the Women's Suffrage Movement

How a constitutional amendment meant to protect Black male voters fractured the women's rights coalition and delayed women's suffrage by 50 years.

By Garret Merkley · Explainer · Jun 4, 2026

Branched from The Shared Roots of Abolitionism and Women's Rights in 19th-Century America

Quick take

The 15th Amendment (1870) granted Black men the right to vote but explicitly excluded women, shattering the unified abolitionist-suffragist alliance.
Women's rights leaders split into two camps: those willing to support the amendment anyway, and those who refused to abandon women's equality.
The amendment's passage convinced many suffragists that women needed their own dedicated movement and constitutional amendment, not shared victories with other causes.
This fracture delayed nationwide women's suffrage until 1920, 50 years after the 15th Amendment passed.

The 15th Amendment, ratified in 1870, prohibited states from denying the right to vote based on race or previous servitude. It was a historic milestone for Black Americans—but it was also a devastating betrayal for women's rights activists. For the first time in American constitutional history, the word 'male' appeared in the Constitution, explicitly limiting voting rights to men. For women who had fought alongside abolitionists for decades, believing their causes were inseparable, this amendment felt like a knife in the back.

The Broken Alliance: When Abolition and Women's Rights Parted Ways

Before the Civil War, the abolitionist and women's rights movements were deeply intertwined. Women abolitionists had been central to anti-slavery organizing, and many male abolitionists supported women's equality. The 1848 Seneca Falls Convention, which launched the organized women's suffrage movement, drew heavily on abolitionist rhetoric and participants. When the Civil War ended and Reconstruction began, women's rights leaders expected their moment had come—that voting rights would be extended to all disenfranchised groups at once.

Instead, Republican leaders made a calculated political choice. They believed securing the Black male vote was essential for maintaining Republican power in the South. They argued that adding women's suffrage to the amendment would make it harder to pass and would distract from the urgent need to protect formerly enslaved men. Many abolitionists who had championed women's rights—including Frederick Douglass—now argued that this was 'the Negro's hour,' not the women's hour. The message was clear: women would have to wait.

The Split: Two Suffrage Movements Emerge

The betrayal of the 15th Amendment forced women's rights leaders to make an agonizing choice, and they split into two irreconcilable camps. Susan B. Anthony and Elizabeth Cady Stanton led the National Woman Suffrage Association (NWSA), which refused to support the 15th Amendment without women's inclusion and began pursuing a separate 16th Amendment for women only. They felt betrayed by male allies and argued that women could not rely on other causes to carry their fight—they needed their own dedicated movement.

Lucy Stone and Henry Blackwell, by contrast, formed the American Woman Suffrage Association (AWSA). They were willing to accept the 15th Amendment as a step forward, even without women, and believed that women's suffrage would follow naturally in time. They favored a state-by-state approach rather than a federal amendment. The split was bitter. For decades, the two organizations competed for resources, members, and strategy, weakening the overall suffrage movement and delaying their reunion until 1890.

How the Amendment Changed Suffragist Strategy

The 15th Amendment's passage fundamentally altered how women's rights activists thought about their work. Before 1870, many believed that women's rights would be won as part of a broader democratic expansion. After 1870, it became clear that women would have to fight alone. This shift had three major consequences: First, it convinced suffragists that a constitutional amendment was essential—state-by-state victories would be too slow and unreliable. Second, it forced women to develop independent political power rather than relying on male allies. Third, it created a more explicitly women-centered movement that, paradoxically, sometimes excluded Black women and other women of color from leadership.

The amendment also exposed a painful reality: the abolitionist coalition had never been as solid as it appeared. Many white men had supported women's rights as long as it seemed compatible with other goals, but they abandoned that support when forced to choose. This lesson stayed with women suffragists for the next 50 years and shaped how they approached alliances with other movements.

Why This Matters: The Long Shadow of 1870

The 15th Amendment's exclusion of women had consequences that rippled far beyond 1870. It delayed women's suffrage by half a century—the 19th Amendment wasn't ratified until 1920. It fractured the coalition between Black rights and women's rights, creating a pattern of mutual exclusion that persisted through the 20th century. Black women, in particular, found themselves abandoned by white suffragists who wanted to focus narrowly on gender, while also being sidelined in Black rights organizations that prioritized male leadership.

The amendment also shaped how American social movements approached intersectionality—though that term wouldn't exist for another century. It demonstrated that movements for different kinds of equality could work at cross-purposes, and that strategic compromises made in the name of progress could have devastating consequences for those left behind. For women's rights activists, it was a hard lesson: they could not assume that allies in one cause would be allies in another.

The Timeline: From Unity to Fracture

Pre-1870: Abolitionists and women's rights activists work together; many expect voting rights to be extended to all disenfranchised groups.
1869-1870: Republicans push the 15th Amendment protecting Black male voters but explicitly excluding women.
1870: The 15th Amendment is ratified. Women's rights movement splits into NWSA (refuses to support) and AWSA (accepts it).
1870-1890: Two competing suffrage organizations weaken the overall movement.
1890: NWSA and AWSA reunite as the National American Woman Suffrage Association (NAWSA).
1920: The 19th Amendment finally grants women the right to vote, 50 years after the 15th Amendment.

Why didn't the 15th Amendment include women?

Republican leaders believed that adding women's suffrage would make the amendment harder to pass in Southern states and would distract from the urgent priority of protecting Black male voters. They also worried that women's suffrage was more controversial and could jeopardize the entire measure. It was a strategic political calculation, not an oversight.

Why did some women's rights leaders support the 15th Amendment even though it excluded them?

Lucy Stone and others in the AWSA believed that securing voting rights for Black men was a necessary step forward, and that women's suffrage would follow. They also worried that opposing the amendment would alienate Republican allies and damage the broader cause of voting rights. It was a pragmatic but controversial choice.

Did the split between NWSA and AWSA really matter?

Yes. For 20 years, the two organizations competed for resources and pursued conflicting strategies, which weakened the suffrage movement overall. Their eventual reunion in 1890 created a more unified and powerful movement, but the delay cost years of momentum and organizing.

How did the 15th Amendment affect Black women's rights?

Black women were doubly excluded—they couldn't vote as women, and the amendment's focus on race meant that Black men's rights were prioritized over Black women's. Many white suffragists also became less interested in racial justice as they focused narrowly on gender, leaving Black women without clear allies in either movement.

Could women have been included in the 15th Amendment?

Possibly, but it would have been politically difficult. There was significant opposition to women's suffrage in many parts of the country, and Republican leaders believed they needed to pass the amendment without women to secure enough votes. Whether this calculation was correct remains debated by historians.

Sources

The 15th Amendment was ratified on February 3, 1870, and explicitly prohibited states from denying voting rights based on race or previous servitude, but did not address gender.
The National Woman Suffrage Association (NWSA) and American Woman Suffrage Association (AWSA) remained separate from 1869 until their merger into the National American Woman Suffrage Association (NAWSA) in 1890.
The 19th Amendment, granting women the right to vote, was ratified on August 18, 1920—50 years after the 15th Amendment.