Early in the Civil War, President Abraham Lincoln was hard pressed by the Radical Republicans -- the party's abolitionist wing -- to abolish slavery by proclamation. Lincoln was opposed. He said that his main concern was preserving the union and he subordinated his feelings about slavery to that goal: "My paramount object is to save the Union, and not either to save or destroy slavery." Moreover, he knew that if he decreed emancipation at the beginning of the war, Missouri, Kentucky, and probably Maryland, all of which technically remained on the Union side, would have joined the South. As the war gloomily dragged on in 1862, and things looked bleak for the Union cause, Lincoln realized that he would have to end slavery. He was willing to issue an Emancipation Proclamation but he felt that the people of the North were not yet ready for it. He needed a military victory. In September of 1862, he barely got one. Five days after the Confederate Army's northward march was stopped at the battle of Antietam on September 17, 1862, Lincoln issued a preliminary proclamation.
in "Jim Crow Stories"