I should have remembered to post this on Tuesday this week, it being 1 January, and so being the 150th anniversary of the Emancipation Proclamation.
That on the first day of January, in the year of our Lord one thousand eight hundred and sixty-three, all persons held as slaves within any State or designated part of a State, the people whereof shall then be in rebellion against the United States, shall be then, thenceforward, and forever free.
You can read the rest here: the Emancipation Proclamation, January 1, 1863.
Here’s a bit more info and context, and below is a picture of some guy showing a copy of the Emancipation Proclamation he has hanging on the wall of his office: