Patrick Hipes Executive Managing EditorBlack Artists for Freedom, a new coalition of more than 1,000 actors, musicians, filmmakers, painters, poets and others, launched Friday with a powerful statement on the occasion of Juneteenth, the holiday that celebrates the official end of slavery in the U.S. 155 years ago.Signees include Barry Jenkins, Ava DuVernay, Dee Rees, Trevor Noah, Roxane Gay, Sterling K.