But if you look at 1860, the bottom map, if you can vaguely see those deep, dark, red areas, you can see where cotton moved, where slavery moved in the domestic slave trade, and then where Southern political power moved.

看看1860年,就在地图的最底部,如果你们能看到这些深红色的区域,你们就能明白棉花种植地的扩大,是如何导致奴隶需求量扩大的,同样变化的还有南方政权力量

耶鲁公开课 - 美国内战与重建课程节选