The movement that sought to end slavery in the 19th century United States is known as the **Abolitionist Movement**. Activists, including influential figures like Frederick Douglass, Harriet Tubman, and William Lloyd Garrison, campaigned tirelessly for the emancipation of enslaved people. They utilized various strategies: speeches, writings, petitions, and the Underground Railroad. The movement gained momentum through public awareness and moral arguments against slavery, leading to significant societal and political changes. Ultimately, the abolition of slavery was achieved with the passage of the 13th Amendment in 1865, marking a fundamental shift in American history and social justice.