How did the Emancipation Proclamation change the course of the war?

Having initially focused on preserving the Union, the Emancipation Proclamation marked a pivotal shift in the American Civil War by refocusing it on the abolition of slavery. It galvanised the Union by strengthening its resolve and enabling Black soldiers to enlist for the first time. Crucially, it undermined the Confederacy, which relied heavily on slave labour. The proclamation also secured international support, deterring European nations from supporting the Confederacy due to widespread anti-slavery sentiment in Europe. Most importantly, by setting a precedent for the abolition movement, it paved the way for the ratification of the 13th Amendment, which formally abolished slavery in the United States.