The proclamation only applied to the Confederacy. The 1863 Emancipation Proclamation was aimed at southern slaves, seeking to weaken southern infrastructure and manpower during the war. It would be only by the very end of the civil war, in 1865, that the Thriteenth Amendment would be passed by the House of Representatives and slavery abolished in the whole nation. It is also worth noting that while the 1863 proclamation did had an effect, the northern government did not had full authority on confederate states and so a post-war proclamation was needed.