January 1, 2013
Epic thing that happened today: Emancipation Proclamation
(Buy this book on Lincoln)
Before that though, Lincoln signed the Emancipation Proclamation on Jan. 1, 1863 which said that all slaves in the Confederate States of America were now free. Obviously the rebellious states still kept their slaves if they could (until the end of the war) and didn't free the 800,000 slaves in the North (that would happen with the 13th Amendment), but it did make the Civil War more about the abolition of slavery than state rights. It kept England from coming into the war on the side of the Confederacy.
(Get Ken Burns' The Civil War Here.)
Perhaps the move was more symbolic, and to ensure that when the country got back together it wouldn't be like the country before the war. Slavery was going to be a thing of the past, and the Civil War was going to accomplish that.
Here's a great article from The Beast that breaks down the signing by Lincoln and just what it means in American history.