What was Abraham Lincoln known for accomplishing while he was president?

Abraham Lincoln is best known for leading the United States through the Civil War and preserving the Union. He issued the Emancipation Proclamation in 1863, which began the process of freedom for America's slaves and laid the groundwork for the eventual abolition of slavery. Additionally, Lincoln delivered the Gettysburg Address, which emphasized the principles of human equality and the importance of national unity. His leadership and vision significantly shaped the course of American history.