History home work question?

Lincoln desired to change the political landscape concerning the civil war. You see at the beginning of the civil war the Northern position was only in the preservation of the Union and not ending slavery. Lincoln agreed to end slavery in the territories and eventually slavery would die its own death. But when the war was not going well despite a ahallow victory at Antietam , Lincoln believed the war needed a new and stronger resolve and thus on September 21, 1862 he issued the Emancipation Proclamation. this was also a great political move since the Congressional elections of 1862 was coming up and the Republicans were losing ground to Northern Democrats who opposed the war and abolitionists who was for the elimination of slavery because it was an affront to God and a national disgrace. Lincoln believed therefore a change in the military and political standpoint of the war was necessary and this proclamation was sent forth to begin on1/1/1863. Opening up the war this way was to hinder the South by decreasing their manpower and morale.