The President who signed the Emancipation Proclamation was Abraham Lincoln.

Issued on January 1, 1863, during the Civil War, this landmark executive order declared that all enslaved people in Confederate-held territory were to be freed. Lincoln's proclamation aimed to weaken the Confederacy's war effort and redefine the purpose of the war to include the fight against slavery. While it did not immediately free all enslaved individuals, it paved the way for the eventual abolition of slavery in the United States and laid the groundwork for the 13th Amendment.