The primary outcome of the Emancipation Proclamation in the U.S. was the declaration that all enslaved people in the Confederate states were to be set free. Issued by President Abraham Lincoln on January 1, 1863, this executive order aimed to weaken the Confederacy during the Civil War. While it did not immediately free all enslaved people, it marked a pivotal shift in the war's purpose, turning it into a fight for freedom and setting the stage for the eventual abolition of slavery in the United States.