Agriculture occurred mainly in rural areas surrounding the ancient city. Agricultural producers could then bring their crops and animal products to the ancient city to sell or trade, but they would not produce within the ancient city.

Cereal grains are typically more shelf-stable than dairy and garden vegetables, and livestock can be transported closer to urban markets for slaughter. Dairy, fruits and vegetables have the potential to spoil rapidly without refrigeration, so traditionally these farmlands are just outside the urban markets.

The development of food surpluses, or more food than farmers need, allows a population of nonfarmers to exist. Those nonfarmers can specialize in the fields and conduct the services needed for the development of cities, which are fed by the farmers. After the development of agricultural surpluses, people can perform nonfarming jobs, including those related to politics, and formal political organizations can subsequently develop. Privitization of land ownership occurred before urbanization and does not influence its trajectory. And currency has been primarily an outgrowth of the social stratification that occurs as trade grows between farmers and nonfarmers.

Housing in urban centers was actually more expensive than housing in rural areas, due to the high value of land. Since cities are much more densely populated than rural areas, the competition for land is greater, driving up the cost of housing.

Transportation in the city of Los Angeles is dominated by the automobile. According to Borchert’s model on the development of cities this is because the city emerged in the early to mid twentieth century, during the auto-air epoch.

The urban geographer John R. Borchert’s model focuses on the development of cities in relation to the development of transportation and communication. According to Borchert’s model a city’s urban layout owes a great deal to what forms of transportation and communication were available when the city was settled.

Borchert’s model of the development of cities tracks the growth of American cities with regard to the prevailing transportation and communication technology of the time period. The auto-air epoch runs from the early twentieth century until the 1970s, it is preceded by the steel rail epoch, which lasted from the 1860s until the early 1900s.

New York City and Boston are two of the earliest American cities. They are both organized around pedestrian traffic, with narrow streets and tall-looming skyscrapers. These are features of cities that emerged during the sail-wagon epoch and the iron-horse epoch.

The sail-wagon epoch is the earliest epoch in Borchert’s model of the development of cities. Seeing as Borchert’s model focuses on the growth of American cities, the sail-wagon epoch begins in 1790 and ends in the early 1830s. It is followed by the iron-horse epoch which lasts until the late 1860s. The iron-horse epoch is followed by the steel rail epoch, which is in turn followed by the auto-air epoch, and finally by the satellite-jet epoch.

Borchert’s model of the development of cities tracks the growth of American cities with relation to the prevailing transportation and communication technology of different eras. The history of American cities is divided into five epochs, the five answer choices listed above. Chicago and St. Louis are two American cities that emerged in the second half of the nineteenth century as railroad hubs. Both these cities developed around the railroad and are classic examples of cities that evolved during the “steel-rail epoch.”