Outside of these areas dominated by large cities and which constitute the armor of US geography, there are mostly rural areas, whose population density depends on the type of agriculture that is practiced there. In the Northeast and around the Great Lakes it is of an intensive type and the population density is high, although here, as in the whole rural territory of the USA, the settlement unit is the isolated farm, with the dwelling house., stables, silos and other outbuildings. The territorial fabric hinges on divisions into townships (squares of 9.6 km on each side, standard divisions dating back to the nineteenth century), to which roads and inhabited centers are adapted. Towns and villages have administrative and commercial functions; they are often county capitals and farms gravitate to them .
These become wider and sparser in the central regions exploited by cereal growing, which have the top of the local territorial organization in the centers located along the railways and in general the communication routes, in relation to the commercial character of agricultural activity. In the South, where plantations dominate, the rural population is also centered on farms and on centers that often retain aspects of the past, with the noble houses of the white aristocratic families and the small miserable abodes of African Americans. In the prairies, where extensive farming predominates, the base of the rural settlement is the ranch, a large farm that stands near the wells, in the center of large grazing areas. Characteristic of the Rocky Mountains are the small towns that arose as mining centers (some, founded at the time of the gold rush, were abandoned and appear as ghost towns) or, in subsequent periods, as tourist, climatic or health resorts. In the Pacific regions there are large and small centers gathered in the most productive areas, such as in the California Valley, whose intensive agriculture has, however, above all promoted the creation of isolated farms. In the South-West, traces of the Spanish past still remain, with the old Catholic missions that have often been the promoters of even urban centers. Finally, the North-West is, like the Great Lakes region, an area of intensive agriculture, rich in farms. Finally, a mention should be made of the numerous small towns of the “province”, centered on Main Street, often of old plant, whose origin is denounced by the name (many times a mythological name, other times that of the English or Italian or Slavic city of the first immigrants who founded it); the structure of the streets is regular, the houses dignified, each with its own garden.
According to 800zipcodes, each center is equipped with the inevitable shopping center in front of which there are vast parking areas for cars that reach it through streets enlivened by advertisements and petrol stations. Overall, however, the population living in farms and small towns is limited, accounting for only 19.2% of the total in the United States. Most of it is considered an urban population, that is, settled in centers with over 2500 residents or in aerial (townships) highly populated even if not occupied by urban agglomerations. The number of large cities is high; however, it is necessary to distinguish real cities (corporated cities) from metropolitan areas (standard metropolitan statistical areas). The American metropolis has already been defined in its structures: wide, extensive, it is made up of endless residential neighborhoods, mostly made up of single-family homes, equipped with shopping centers, which orbit around the City or, better, the Central Business District, an area sacred to financial and economic business, dominated by skyscrapers. New York and Chicago are the most spontaneous and exalted expressions of the American metropolis, both developed in their vertical and horizontal gigantism starting from the century. XIX, with the competition for the grabbing of the building space that was reduced with the swelling of the population. Both have maintained, in distinct neighborhoods, the different nationalities: the Italians, the Jews, the old Anglo-Saxon aristocracy, the blacks, the Puerto Ricans, etc. Over the years, real ghettos have continued to expand in the central areas, gradually abandoned by the more affluent population, who look for more hospitable environments in the suburbs, even far away, than the run-down neighborhoods of cities., which have become squalid and unbreathable asylums for the most disinherited people. New York is the most striking example of this evolution of the American city: just think of the famous African American neighborhood of Harlem, which is also located in the borough of Manhattan, the economic and cultural “heart” of the metropolis. From the nineties of the twentieth century and then with greater vigor at the beginning of the twenty-first century, through colossal urban redevelopment projects, there has been a return of the wealthy component of the population to the historic districts, through the enhancement of the original disused buildings. Harlem and the East Village, for example, have undergone an unexpected and unthinkable renaissance in the previous decades: these centers exhibit new residential and commercial areas, with restaurants, trendy shops etc. The risk, however, is that the poorest residents of these neighborhoods, which make up the historical element, are forced to abandon it due to the increase in property prices.