Effects of the Emancipation Proclamation

In the context of the Civil War, the Emancipation Proclamation issued by President Abraham Lincoln had significant implications not only for enslaved individuals but also for the war effort itself. Lincoln's decision to issue the proclamation was influenced by various factors, including military strategy and moral concerns regarding slavery. It is essential to understand the immediate and long-term effects of this historic document. Which of the following statements accurately describes one of these effects?