Final answer:
The Emancipation Proclamation had limited immediate impact on slaves because it only freed those in rebelling Confederate states, where it was not recognized.
Step-by-step explanation:
The Emancipation Proclamation is a historical document that had mixed impact when it was issued during the American Civil War. Its immediate effect on slaves was limited due to the fact that it only declared the freedom of slaves in Confederate states, which were in rebellion and did not recognize the authority of President Lincoln or federal law. This meant that in areas where the Proclamation could have had direct legal force, its power was negated by active conflict and non-recognition by Confederate authorities. Furthermore, the Proclamation did not apply to slave-holding border states that remained in the Union or specific regions in the South already under Union control. Critics, including Secretary of State William Seward, observed this limitation with the statement "Where he could, he didn't. Where he did, he couldn't."
Despite the initial limited scope, the Proclamation represented a pivotal shift in the Union's war aims, indicating a transition from a goal of reunification to the inclusion of abolition of slavery. This strategic move also undermined any remaining Confederate hopes of gaining support from the United Kingdom, which held strong anti-slavery sentiments. As the war progressed and Union forces advanced, the Emancipation Proclamation also provided a legal framework for the liberation of slaves, who began to leave plantations and head towards Union camps. This influx of freed slaves not only undermined the Confederate economy but also bolstered the ranks of the Union army with nearly 200,000 black soldiers who played a significant role in the eventual Union victory.
Despite its limitations, the issuance of the Emancipation Proclamation was a critical step on the path to ending slavery in the United States. It provided a rallying point for abolitionists, influenced international opinion, and led to the enlistment of black soldiers in the Union army, which was instrumental in shifting the tide of the war.