The Union Army had greater access to supplies due to their largely industrial economy.

The Union Army under General Sherman ruthlessly destroyed Confederate supply lines, cities and crops.

As the war drug on the Confederate Army began to suffer from troop shortages and Confederate soldiers succumbed heavily to disease, starvation and injury.

After Linclon declared the Emancipation Proclamation law, other countries were afraid to give aid the the South. The War for States Rights had now become a War over Slavery. Neat trick huh? One side note...Lincoln gave up his slaves just before issuing the proclamation but he allowed his wife, Mary to keep hers after the proclamation. Do you think he issued the proclamation, knowing it would hurt the South?

The Emancipation Proclamation did not free any slaves. It's sole purpose was to keep any foreign interference at bay by making the war a question of slavery. Of course this would shut a door of support for the Confederacy, which was seeking foreign assistance.

The Proclamation told the Confederacy to return to the Union within one hundred days and you can keep your slaves - or be compensated for them, when and if the law takes them away. Otherwise, if you lose the war, you lose your human property as well. It proclaimed freedom only for those unfortunates now firmly under Confederate control. Lincoln proclaimed emancipation only where he has no power to execute it. Not only were the loyal or semi-loyal slave states of Delaware and Maryland, Kentucky and Missouri omitted from the terms to be applied, but so was the whole rebel state of Tennessee, as well as those parts of Virginia and Louisiana under Federal occupation.

Superior intellect!