By EP is presume you mean the Emancipation Proclamation.
Of course the EP did not address slaves in Missouri, Kentucky, Maryland, Delaware or the District of Columbia, where the institution was legal. Nor did to apply in areas occupied by the Union Army such as New Orleans or much of Northern Tennessee. The Dred Scott Decision stated that the Federal Government could not interfere with slavery in any state where it was legal, it was a State Right. Lincoln recognized that fact. Since 11 states had seceded from the Union and were in armed rebellion against the United States, Lincoln reasoned that freeing the slaves in only those states in secession was within his authority as the Commander and Chief of the United States armed forces. Slave were used to build fortification, produce food for Confederate armies, work in factories manufacturing weapons and munitions for the Confederate army, driving wagons, and repairing rail roads to transport provisions, equipment, weapons and ammunition to Confederate forces. Slave were being used to support the Confederate war effort against the United States. That is why the EP did not include northern slaves and slave owners. It was aimed at limiting the Confederacies ability to make war. OBTW, the EP was discussed quite extensively in the public schools I went to, but maybe not the ones you went to.
Now if you could complete your education and investigate why they seceded. Which by the way, the Founding Fathers provided for.