It's official.
"The Emancipation Proclamation, officially Proclamation 95, was a presidential proclamation and executive order issued by United States President Abraham Lincoln on January 1, 1863, during the American Civil War. The Proclamation had the effect of changing the legal status of more than 3.5 million enslaved African Americans in the secessionist Confederate states from enslaved to free."
https://en.wikipedia.org/wiki/Emancipation_Proclamation