Abraham Lincoln Speaks Out Against Slavery

What Happened?

The Kansas–Nebraska Act (1854) said people in two new territories could decide for themselves whether to allow slavery, a policy called “popular sovereignty.” Lincoln believed this erased earlier compromises that tried to limit slavery’s spread and keep the nation stable.

At Peoria on October 16, Lincoln explained that America had a long pattern, through the Northwest Ordinance, the Missouri Compromise, and other laws—of containing slavery rather than spreading it. The Act, he argued, broke that pattern and invited conflict.

Lincoln used clear moral language for a young nation to grasp: if enslaved people are human beings, then “all men are created equal” must apply to them, too. That means no one has a moral right to own another person.

He challenged the idea that a vote alone could make slavery acceptable. For Lincoln, majority rule mattered—but not when it violated basic human rights. In a democracy, freedom and equality set the rules for what majorities can decide.

Some said climate and geography would keep slavery out of Kansas and Nebraska. Lincoln answered with facts: when slavery is legal, it expands; when it’s illegal, it shrinks. Laws shape real lives, not just maps.

Lincoln focused on stopping slavery’s expansion, not ending it everywhere at once. He believed containing it would place it “in the course of ultimate extinction,” reducing the risk of immediate civil war while still honoring American principles.

Peoria also showed Lincoln’s method: history plus morality. He quoted the Founders, traced past laws, and then asked the simple question kids can ask, too—Is it fair? If not, why should we allow it to grow?

Newspapers noticed. An “obscure” Illinois lawyer became a national figure who could explain big ideas in everyday words. The Peoria Speech helped lead to the Lincoln–Douglas debates, a presidential run in 1860, and eventually the end of American slavery.

Why It Matters

Lincoln’s Peoria Speech teaches that democracy is more than voting; it’s voting guided by values. By insisting that human rights set limits on what laws can do, Lincoln connected the nation’s founding promise to the lives of real people. His stand against expanding slavery helped steer the country toward a more faithful version of “all men are created equal.”