Final answer:
The Emancipation Proclamation did not free slaves in the Union states initially; it only declared slaves in the Confederacy free as a war strategy. The Thirteenth Amendment, ratified in 1865, legally ended slavery throughout the United States.
Step-by-step explanation:
The Emancipation Proclamation issued by President Abraham Lincoln during the Civil War initially did not free slaves in the Union states. Instead, it declared that slaves in the Confederacy — those areas still in active rebellion against the United States — were deemed "henceforth and forever free." This measure, taking effect on January 1, 1863, was a war strategy that aimed to undermine the Confederate states' resources.
Slaves in the Union states were not immediately freed by this proclamation; rather, their freedom was legally binding after the ratification of the Thirteenth Amendment in 1865. Lincoln was careful not to alienate the Union border states that still allowed slavery, as he did not want to lose their support during the war. His stance was a delicate balancing act, viewing emancipation both as a necessary step for the preservation of the Union and a moral imperative. Ultimately, the Thirteenth Amendment was essential to grant freedom to all slaves, as it provided the constitutional basis to permanently abolish slavery in the United States.