After the costly Union victory at Antietam in September 1862, Abraham Lincoln issued the Emancipation Proclamation in January 1863. While the document did free enslaved people living in the states under rebellion, Lincoln was careful to balance military and political realities. The proclamation did not affect enslaved people living in the border states nor the parts of the Confederate states under the control of the Union Army. However, not only did the Emancipation Proclamation persuade Britain and France to avoid allying with the Confederacy, it shifted the priorities of the northern war effort from saving the Union to both saving the Union and ending slavery.