why did the EP not apply to all states?
http://www.pbs.org/wgbh/aia/part4/4h1549.htmlThe Emancipation Proclamation did not free all slaves in the United States. Rather, it declared free only those slaves living in states not under Union control. William Seward, Lincoln's secretary of state, commented, "We show our symapthy with slavery by emancipating slaves where we cannot reach them and holding them in bondage where we can set them free."
Lincoln was fully aware of the irony, but he did not want to antagonize the slave states loyal to the Union by setting their slaves free.The proclamation allowed black soldiers to fight for the Union -- soldiers that were desperately needed. It also tied the issue of slavery directly to the war.