Emancipation had not initially been a U.S. war aim. As the Union death toll mounted however, support grew for striking a blow against the institution that helped sustain the Confederacy. After the U.S. victory at Antietam in September 1862, Lincoln announced that on January 1, all slaves in rebellious states would be freed.
The proclamation had little immediate effect on the South’s 4 million enslaved, but it made abolition a Union war aim, and as the U.S. Army advanced into the Confederacy, it became an army of liberation. The proclamation also made it possible for nearly 200,000 African-Americans to join The United States Armed Forces during the war.
For the 400,000 enslaved Georgians, the Emancipation Proclamation laid the foundation for a new social order when it was issued January 1, 1863, Today in Georgia History.
Slavery continued to exist legally in some areas until the 13th Amendment was ratified on December 18, 1865.