John Singleton's "Rosewood'' re-creates the story of a shameful event in American history, the race riot by whites against blacks in 1922 in the small Florida town of Rosewood, which left the town in smoking ruin while dozens of its residents were shot, burned to death or lynched. But if the movie were simply the story of this event, it would be no more than a sad record. What makes it more is the way it shows how racism breeds and feeds, and is taught by father to son.