He came up with the Emancipation Proclamation shortly after meeting with Union leaders. The proclamation was a controversial decision that went against the general rules of the past. The Emancipation Proclamation declared slaves in the states still in rebellion to be free. By the time of the final Emancipation Proclamation on January 1, 1863, Lincoln had concluded his act to be a war measure taken by the Commander in Chief to weaken the enemy. .
"Now, therefore, I, Abraham Lincoln, President of the United States by virtue of the power in me vested as Commander-in-Chief of the Army and Navy of the United States, in time of actual armed rebellion against the authority and government of the United States, and as a fit and necessary war measure for suppressing said rebellion, do.Order and declare that all persons held as slaves within said designated States and parts of States are, and henceforward shall be free (Williams)." This released property from the South and limited the economy. The plantation owners denied many of the slaves' freedoms, causing them to flee to the north. If captured on the battlefield, they were seen as slaves instead of soldiers. They were put on trial to be punished and prosecuted under different standards. Black soldiers from the North had provisions against them being armed which affected the Union when drafting black soldiers. Prisoner exchanges were also affected by the black soldiers. The South would not trade the black captives for white prisoners. "The Union position, unless black soldiers are included no exchanges will be made. The Union continued to offer exchanges so long as the south will enter into them with black soldiers equally (Witt)." Lincoln looked for another way to concisely settle disputes between the Confederacy and the Union. .
After a terrible defeat in Virginia, Lincoln issued a new set of laws. Written by a committee of veteran Union officers led by Professor Francis Lieber, the code updated the laws of war for modern conditions.