Explain how changes in transportation, from trails and horses to railroads to automobiles and highways, changed how towns grew and where they were located.
How people travel changes where and how a town grows. Long ago, towns often grew up near a river crossing or a trail junction, because that is where foot and horse traffic naturally passed through. When railroads arrived, towns often grew up around the train depot instead, since the railroad could move people and goods much faster and much farther than a horse and wagon.
Later, cars and highways changed towns again. Once people could drive quickly across longer distances, they could live farther from downtown and still get to work or school easily, which is part of how many suburbs grew. A new highway could also change a town's Main Street overnight: if the highway bypassed downtown, some old Main Street businesses lost customers who now zoomed right past on the highway instead.
Mastery looks like: They can explain, in order, how trails, railroads, and highways each changed where and how towns grew.
Common stumbles: Assuming towns have always been shaped the way they look today, without connecting their layout to real transportation history.