The major historical movement that sought to abolish slavery in the United States is known as the Abolitionist Movement. This movement gained significant momentum in the early 19th century, driven by moral, humanitarian, and political arguments against the institution of slavery. Prominent figures emerged, including Frederick Douglass, Harriet Tubman, and William Lloyd Garrison, advocating for immediate emancipation and equal rights for African Americans. The movement laid the groundwork for the legislative changes that followed, culminating in the Emancipation Proclamation in 1863 and the eventual passage of the 13th Amendment in 1865, which formally abolished slavery in the United States.