Emancipation Proclamation and the Effect on War
The official US Government position in the Civil War from 1861 - January 1st 1863 was to preserve the Union, not to ban slavery. The Emancipation Proclamation issued in Sept 1862 to take effect on January 1863 changed that.
Britain and France was meddling in the war on the Confederacy's side (sending military ...view middle of the document...
The UK and France were on the verge of recognizing the Confederacy and actively intervening in the war on the Confederacy's side. With the issuance of the EP, France and the UK were scared off. They hated slavery.
The EP actually freed no slaves. It was issued in Sept 1862 and said that all slaves still in the Confederacy on 1 Jan 1863 were to be freed. The slaves in Union areas (slave states of Kentucky, Montana, Delaware, and Maryland; Union-occupied areas of the Confederacy in Tennessee and Hampton Roads area Virginia; and Wash DC) remained slaves. It allowed for Confederate States who rejoined the union prior to January to keep their slaves. Since Lincoln's authority was not recognized by the Confederacy, they ignored the order to free their slaves on January 1863.
So while the EP freed no slaves, it turned the purpose of the war from preservation of the Union to freeing the slaves and scared off France and UK. So yes, the EP had a huge effect on the war.