Did Lincoln free the slaves?

The popular shorthand that Lincoln freed the slaves is true in spirit but importantly incomplete in the details. Lincoln's Emancipation Proclamation, issued January 1, 1863, was a war measure that declared enslaved people free specifically in the Confederate states then in rebellion, not in the border states that had stayed in the Union, and it had no immediate practical force in areas the Confederacy still controlled. In effect, freedom arrived where and when Union armies advanced and enforced it, which is why celebrations like Juneteenth mark the day (June 19, 1865) that news and enforcement finally reached enslaved people in Texas, more than two years after the Proclamation. So the Proclamation was a pivotal turning point, transforming the war's purpose and authorizing Black men to fight for the Union, but it did not by itself end slavery everywhere.

Legal, permanent, nationwide abolition came from the Thirteenth Amendment to the Constitution, ratified in December 1865 after the war, which formally abolished slavery throughout the entire United States, including the border states the Proclamation had exempted. Lincoln pushed hard for that amendment and was assassinated months before it was ratified. And the fuller history credits more than one man: enslaved people themselves resisted, escaped, and pressed the issue relentlessly, tens of thousands fleeing to Union lines and nearly 200,000 Black soldiers and sailors fighting for their own freedom, abolitionists had agitated for decades, and Congress passed the amendment. So the honest answer is that Lincoln was central and his Proclamation was a landmark, but slavery was ended through the Thirteenth Amendment, enforced by Union victory, and driven throughout by the actions of enslaved people fighting for their own liberation, not by a single stroke of one president's pen.