Prior knowledge necessary. A bit of background 2 assumptions: 1. The US population has always had strong racist elements; 2. Americans generally believe in the creed of equality.
“Are we to say to the world-and much more importantly, to each other-that this is the land of the free, except for the Negroes?”
“[black] Citizens of the United States have been shot, set upon by vicious dogs, beaten and otherwise terrorized because they sought to vote.”