The Emancipation Proclamation stated that slaves in the Confederate states (the states that wanted to separate from the United States) were free, and that the Union military would fight to preserve that freedom. It applied only to states that were “in rebellion against the United States.” Declaring that those slaves were now free was considered a “fit and necessary war measure for suppressing said rebellion.”

The Proclamation’s second paragraph introduces the general sense of the terms:

“That on the first day of January, in the year of our Lord one thousand eight hundred and sixty-three, all persons held as slaves within any State or designated part of a State, the people whereof shall then be in rebellion against the United States, shall be then, thenceforward, and forever free; and the Executive Government of the United States, including the military and naval authority thereof, will recognize and maintain the freedom of such persons, and will do no act or acts to repress such persons, or any of them, in any efforts they may make for their actual freedom.”

The Proclamation did not simply declare that slaves were free. In the same document, the Government invited the newly freed slaves to join the Union cause and fight against the rebelling Confederate states: “And I further declare and make known, that such persons of suitable condition, will be received into the armed service of the United States to garrison forts, positions, stations, and other places, and to man vessels of all sorts in said service.”

In 1862, the U.S. Government Printing Office in Washington, DC, printed 15,000 copies of the preliminary Emancipation Proclamation for the War Department. The Proclamation was distributed to military commanders, troops, and diplomats in foreign countries. The proclamation was an important moment in abolishing slavery in the United States. It paved the way for the passage of the 13th Amendment to the Constitution, in December 1865, which ended slavery permanently in the United States.