Karlos K. Hill and Soraya Field-Fiorio (TED-Ed narration/content)

One day, while hiding in the kitchen, Charlotte Brooks overheard a life-changing secret.

At the age of 17, she'd been separated from her family and taken to William Nealon's Texas plantation.

There, she was made to do housework at the violent whims of her enslavers.

On that fateful day, she learned that slavery had recently been abolished, but Nealon conspired to keep this a secret from those he enslaved.

Hearing this, Brooks stepped out of her hiding spot, proclaimed her freedom, spread the news throughout the plantation, and ran.

That night, she returned for her daughter, Tempe.

And before Neelan's spiteful bullets could find them, they were gone for good.

For more than two centuries, slavery defined what would become the United States, from its past as the 13 British colonies to its growth as an independent country.

Slavery fueled its cotton industry and made it a leading economic power.

Ten of the first 12 presidents enslaved people.

And when U.S.

chattel slavery finally ended, it was a long and uneven process.

Enslaved people resisted from the beginning by escaping, breaking tools, staging rebellions, and more.

During the American Revolution, Vermont and Massachusetts abolished slavery, while several states took steps towards gradual abolition.

In 1808, federal law banned the import of enslaved African people, but it allowed the slave trade to continue domestically.

Approximately 4 million people were enslaved in the U.S.

when Abraham Lincoln was elected president in 1860.

Lincoln opposed slavery, and though he had no plans to outlaw it, his election caused panic in southern states, which began withdrawing from the Union.

They vowed to uphold slavery and formed the Confederacy, triggering the start of the American Civil War.

A year into the conflict, Lincoln abolished slavery in Washington, DC, legally freeing more than 3,000 people.