brick
Contrary to the popular opinion American Midwest is a great place to live if you are looking for an urban environment: Omaha in Nebraska, Sioux City and Dubuque in Iowa, Madison and Milwaukee in Wisconsin to name just a few that we’ve passed. Even Chicago - although The Windy City is obviously in a league of its own. Incidents of history made them busy industrial towns at the time when brick was the nonflammable material of choice. The warehouses and factories had to be built near city centers. Transportation was either slow, by horse drawn wagons, or inflexible by rivers and trains. Just-in-time production has been a thing of the future missing the crucial component: a real-time inventory tracking. One needs computers for that and Victorian inventors somehow have not progressed from theory to practice. Hence the need for large space devoted to storing raw materials, components and finished products around factories. What results are solemn permanent structures: large enough to impress and provide some backbone to the city grid. Small enough not to intimidate unsuspecting pedestrians.
corn
All the states that we have crossed so far have sections that are uninhabited. Mountains, forests, deserts and other natural obstacles stand in the way of human conquest. Not so in Iowa. Incredible 99% of land is put to a productive use. With the exception of a few cities this means agriculture. Specifically, fields of corn. In a 100 years of settlement Iowa was so successful in cultivating prairie that at the turn of the 20th century there was none left for the federal government to put its paws on and convert into a national park as it was tempted to do in other states.