Which significant action is Abraham Lincoln known for?

Abraham Lincoln is prominently known for issuing the Emancipation Proclamation, which was a critical moment in American history during the Civil War. This executive order, signed on January 1, 1863, declared the freedom of all enslaved people in the Confederate states. This action not only aimed to weaken the Confederacy by disrupting its labor force but also set a moral standard for the war by positioning it as a fight against slavery. The Proclamation paved the way for the eventual abolition of slavery throughout the entire nation with the ratification of the 13th Amendment. Lincoln's emphasis on liberty and equality through this proclamation marked a pivotal shift in both public policy and social consciousness in the United States, solidifying his legacy as a champion of human rights.