The US ranks third in the world by population, after China and India. At the census in 1990 the population was 248, 7 million, but an estimate of 2000, which also takes account of illegal immigrants, the currency in 274. 546. 000 residents the population of the country. For 2010 it is forecast around 300 million and 325 for 2020. In fact, unlike other industrialized and advanced countries, the US maintain a rather high birth rate, between 15, 2 and 15,6%, and an almost constant mortality rate for years, between 8, 5 and 8, 7%, with a natural rate of increase that is still largely positive. There remain differences between the white majority (80 %) and a very important historical minority and the black (12, 2 %), which maintains a higher infant mortality rate and a higher average birth rate, so that the number of young people in of the black population is higher. Legal immigration is around 400. 000 people per year (1985 – 95), with an increasingly unique composition by language, Spanish, and origin, Mexico and Central America. If illegal immigration is added to this legal immigration, largely coming from the same regions (but in particular from Mexico), the picture is clearly delineated according to a short-term forecast. Illegal immigration is difficult to estimate, perhaps oscillating between 100. 000 and 300. 000 people a year, while the linguistic-cultural origin is almost univocal, unlike the old European immigration, which was very composite, on which the English language acted as a common vehicle of communication accepted by all.
Seasonal immigration, especially Mexican, is widely practiced especially for agricultural work; this phenomenon, which has been traditional for decades in California and Texas, is experiencing new developments, as tens of thousands of seasonal workers are employed in the historic South (Dixie), especially in the Carolines and Georgia, for the collection and processing of tobacco, peanuts and even cotton in numerous refugee camps.
Currently Spanish is the second language of the US, although English remains the only official language: as well as in some Southwestern states, such as California, Arizona, New Mexico, Texas, where on the ancient Hispanic tradition there is a strong immigration from Mexico, large Hispanic minorities are present in New York, Chicago, Miami and other large metropolitan areas. In addition to immigration from Mexico and Central America, there is traditional immigration from Puerto Rico, an Associated State (Puerto Ricans are citizens of the US), where the official languages are Spanish and English. Legal residents who speak Spanish were 22, 4 million at the census in 1990, but adding together illegal immigrants and those awaiting permanent residence and citizenship, albeit at the level of hypothetical estimates, it exceeds 26 million; the census of 1980, the minority ‘Hispanic’ officer was 14, 5 million and in 1987 was already estimated at 19 millions: this large and rapidly growing minority, fueled by continuous migratory currents, could surpass the historical one of the Blacks, who instead are native English speakers. The compactness of recent Hispanic communities means that Anglophone linguistic assimilation is often rejected; there are now numerous television channels in Spanish, schools in which parents demand the use of the Spanish mother tongue, and bilingual signs appear in some states; in the supermarkets of large chains in the southern southwestern belt and in some counties of Florida, Spanish is commonly used together with English and so is the case for shop signs, not only in neighborhoods inhabited by Hispanics (J. Garreau, in a 1981 essay, The nine nations of North America, already hypothesized a southern cultural ‘nation’, called Mexamerica, with no political border with Mexico).
The share of the urban population is now substantially stable (75 % at the 1990 census, 77 % according to 1998 estimates). The total number of residents in MSAs (Metropolitan Statistical Areas), which may also include non-urban areas (for the criteria followed in their institution, see united states, in App. V, p. 239), already exceeded 200 million in the first the nineties. Some of the largest MSAs, together with numerous other medium-large ones, are included in three colossal urbanized regions which, according to the model proposed by J. Gottmann in the 1960s, can be defined as megacities, because they group constellations of cities, including huge expanses of outlying middle-class settlements, the outer cities. The first is that the Atlantic megalopolis, between Boston and Washington, and includes the metropolitan areas of New York (19, 5 million pop.), Philadelphia (5, 9) and Baltimore (2, 4); the second is that of the Great Lakes, which hinges on the Chicago metropolitan area (8 million) and can be estimated to extend from Milwaukee to Buffalo, through Detroit (4, 7) and Cleveland (2, 8), with an extension on Canadian territory in Toronto; the third megalopolis California, from San Diego (2, 5 million), San Francisco (6, 5), through the huge metropolitan area that is owned by Los Angeles (15, 5) and the traditional settlements (like Sacramento) or the more recent ones from the Central Valley. However, the most vital metropolitan areas, which have increased in population in recent years, are almost always external to these megalopolitan formations. So, Atlanta (2, 9 million), Georgia, Denver (2) in Colorado, Seattle-Tacoma (2, 9) in the State of Washington and especially the Texas metropolises Dallas-Fort Worth (4) and Houston (3, 8) appear as the main urban realities in expansion.
The pushed suburbanization has produced a new type of service centers, scattered on the fringes of the primeval urban areas, the edge cities that replace the old downtown. They are necessary for the life of very large residential suburbs, as an extreme transformation of urban life projected into the near future. The edge cities are functional centers as centers of attraction of services, in which migrates and is divided, with multicentrali functions, the traditional role of the central inner city as a center provider of qualified services: are new and many downtowns dotted around the old inner cities. These ‘peripheral central poles’ group tall buildings, sometimes real skyscrapers, large and capable parking lots, offices, various shopping centers, hotels of prestigious or otherwise good quality chains, as well as theaters, first-run multiplex cinemas, high-end restaurants. medium-high and other leisure services and, not infrequently, industries migrated from the innermost urban areas. Other related businesses often open up near them, such as vast commercial plazas where giant supermarkets operate, retail businesses, restaurants of various categories and even residential buildings. Motorway bridges, fast junctions, expressways and a smaller network of efficient roads connect these centers both to the old downtown, and to the motorway network, to the interstate highways (federal highways) or turnpikes, toll highways managed by private companies or mixed consortia: about 70 % of the most vital and dynamic service sector operates in the context of these new urban realities. There are about 300 consolidated or advanced edge cities in the United States. Many are located within the megacities described above, others on the fringes of expanding metropolitan areas. Their counterpart, widespread but with a modest socio-economic impact, is gentrification, i.e. the recovery and reuse of historic buildings (even 60 or 70 years old) in the centers of inner cities. Another relatively recent phenomenon, because it is widespread in the middle class and no longer only among the restricted population groups with very high incomes, concerns the development of ‘fortified’ suburban residential areas, that is, guarded by armed and fenced-in guards, sometimes equipped with sophisticated security systems. electronic security.
The territorial mobility of the population is traditionally high, so changing residence and job several times in a lifetime is considered quite normal. The most desirable areas are located in the Sun Belt: first central-southern California, Arizona, New Mexico, Texas, Florida; alternative destinations cover areas of Louisiana, various regions of the historic South (especially the Carolines, Georgia, the Alabama coast) and the Northwest (Northern California, Oregon, Washington State). The Rust Belt(i.e. the mid-Atlantic region joined to that of the Great Lakes) and the Frozen Belt (“frost belt”, that is the region of the Great Lakes together with the central-northern belt of the Great Plains, with a continental climate with severe winters) have lost population for twenty years, only to stabilize and slowly increase in some revitalized district and in some MSAs only since the 1990s. The Sun Belt, on the other hand, is constantly increasing. Two particular phenomena emerge: the return of Blacks to the historic South, in the most developed and evolved metropolitan areas, that is to the places from which their families emigrated in the past, and the migration of pensioners with medium and medium-high incomes to Florida, Arizona, some areas of Southern California, in search of more favorable climatic conditions. The center of population, that is, the demographic center of gravity of human settlement in the US, which at the 1990 census was located in Missouri, continues to move towards the West and especially towards the South, testifying the growing propensity of the population for the Sun Belt.