I ran across a Norman Rockwell painting I've never seen before, called Southern Justice. This depicts the murders of the three civil rights workers in Mississippi. As I understand it, this is Rockwell's color sketch, which Look magazine chose over the finished painting, but I'm not sure if it was actually published or not. At any rate, a powerful, masterful work.
(Note: This is the final painting, as a reader pointed out. The looser sketch was used in the magazine.)