Answer:
President Lincoln declared that Emancipation proclamation on 1st Jan 1863 to free the slaves within the rebellious territories. But it only applied to the states that had seceded from the US while it exempted the loyal states and the territories won by the Union.
Emancipation proclamation didn't end slavery but it did announce acceptance of black men into Union Navy and Army. Almost 200,000 black soldiers fought for the Union.