On September 22, 1862, President Abraham Lincoln issues a preliminary Emancipation Proclamation, which sets a date for the freedom of more than 3 million black slaves in the United States and recasts the Civil War as a fight against slavery.
On September 22, 1862, Lincoln issued a preliminary warning that he would order the emancipation of all slaves in any state that did not end its rebellion against the Union by January 1, 1863. ... The Proclamation made freeing the slaves an explicit goal of the Union war effort.