On September 22, 1862, President Abraham Lincoln issued a preliminary Emancipation Proclamation following the Union victory at Antietam. The proclamation declared that enslaved people in states still in rebellion would be free as of January 1, 1863, if those states did not return to the Union. It shifted the Union war aim to include the abolition of slavery, not only preservation of the Union. The announcement discouraged foreign governments from recognizing the Confederacy. It also encouraged many enslaved people to seek freedom behind Union lines and paved the way for the Thirteenth Amendment.
