The Emancipation Proclamation itself took effect only as the Union armies advanced into the Confederacy.
Near the end of the war, Republican abolitionists were concerned that the Emancipation Proclamation would be construed solely as a war act and thus unconstitutional once fighting ended.
The Emancipation Proclamation was a presidential order in 1863 that proclaimed freedom to all slaves in the Confederate States of America.
The Emancipation Proclamation was never tested in court one way or the other, but no court or legal scholar has questioned its validity.
The Emancipation Proclamation also allowed for the enrollment of freed slaves into the United States military.
Some man who seemed to be a stranger (a United States officer, I presume) made a little speech and then read a rather long paper—the Emancipation Proclamation, I think.