Answer:
The use of the 13th Ammendment (Emmancipation Proclamation) as a tool to further isolate the South during the Civil War, was also the strategy to eliminate the inmediate reason of the war.
Explanation:
The final defeat of the Confederacy can be explained by its failure to procur an international recognition. And one of the key factors in this was the slavery issue. European powers, that had abolished slavery between 1830-1850, did not wanted to be associated to it, but weighted their options until the Union blockade of the South ports, and military victories seemed to define the course of war.
This was also fostered by the injection of recruits of African-American origin into the Union's army such as the Massachussets 54th regiment (portayed in the film "Glory").
It would be the economic policy of "mercantilism" that was based on the idea that the American colonies primarily were meant to provide economic benefits for Great Britain, since this philosophy held that trade between two entities benefits mainly the larger entity (in this case Britain), and that it is in that entity's best interest to protect its trading partner (the colonies).
