ABSTRACT
Simple diagrams are easily understood and become the dominant metaphors for cultural understanding. Consider a typical left-right political diagram. Diagrams in history class are better when they are quick and easy to draw. Unlike published infographics, they don't need labels and clutter, so long as the professor properly explains the bounds and metrics of the diagram. In the design industry, printed diagrams that require explanation are poor diagrams. But in a classroom, diagrams don't need to stand alone. On the eve of the Civil War, most Americans held ambivalent views about the nature of slavery and its persistence in the nation. A larger table or matrix can be useful to structure an entire lecture, or to prepare for an exam. The typology of historic inscriptions in the Grand Caverns shows in general form how patterns of carving names changed over time.
