Why was the Emancipation Proclamation created?

It was primarily to make the American Civil War a war of freedom against slavery from the Unionists against the Confederates

The Emancipation Proclamation was a military tactic from the North. Lincoln declared any enslaved people in ceded states free, allowing them to find sanctuary in the Northern states. When finding refuge in the North, they were also encouraged to join the Union Army, bolstering Lincoln's troops in the Civil War.