The Emancipation Proclamation was a law passed on September 22, 1862 by President Abraham Lincoln, and it came into force on January 1, 1863, abolishing slavery throughout Confederate territory even in the Civil War and making the abolition of slavery a main objective for the Union.
At the time of its ratification, the Proclamation freed a minimum number of slaves, but as the Union annexed the Confederate territories, it opened the way for the total abolition of slavery in the American territory. Slavery became illegal through the approval of the 13th Constitutional Amendment, a fact that occurred in 1865.
The law was severely criticized in the southern states, whose economic activity was based on slave labor. However, adherence to this measure in all Confederate states ensured Lincoln's main focus: strengthening the Union's ties.