Abraham Lincoln's Emancipation Proclamation was significant as it declared the freedom of all enslaved people in Confederate-held territory. Issued on January 1, 1863, this executive order aimed to weaken the economic foundation of the Confederacy. While it did not immediately free all enslaved individuals, it transformed the Civil War into a moral fight against slavery and shifted the Union's war goals to include the eradication of slavery, laying the groundwork for the future 13th Amendment.