The Georgia Negro: A Social Study - Graph shows percentage of enslaved African Americans compared to free African Americans from 1790 to 1870 [LCCN2013650431]
The pattern
This still is filed under Data as proof.
Define
A chart, map, or count that is the argument, not an illustration next to the argument.
Mechanism
Sighted evidence. The reader is asked to believe their eyes: a bar, a share, a spread on a map.
Verdict
The claim is comparative or quantitative and the figure can be read without a caption doing the sell.
Why it works
The chart is deliberately mis-scaled against its own subject: the top axis only counts to three percent, so a boundary that barely moves for eight decades still reads as a jagged, struggling line. That makes the last band land like a cut - the same visual language, suddenly filled the other way. Running the two categories inward from opposite edges instead of stacking them left to right means the eye tracks one contested seam rather than comparing two bar lengths. The right-hand numeric column lets a sceptic check the drawing without breaking the picture.
Steal this when
Use this shape for a long flat series that ends in a discontinuity - zoom the scale so the flat stretch still has texture, keep every period visually identical, then let the final row break the pattern with no annotation at all.