Since the Declaration of Independence on 4 July 1776, the size and extent of the United States of America has changed and grown; the current extent dates from 1959, with the entry of the islands of Hawaii as the 50th state in the union. The government of the country has alternated between the two major parties: Democratic (Dem) and Republican (Rep).
The USA is a federal republic comprising 50 states (each with its own governor and legislature, both directly elected) plus the Federal District of the capital. In accordance with the Constitution, the President is elected (together with the Vice President) on a four-year mandate, by an electoral college, itself elected by the electorate; he or she may be re-elected once only. The President holds executive power with the assistance of a presidential cabinet formed of the heads of department (ministers) appointed by him and reporting directly to him. The President can promote bills and has the right of veto; he also appoints the Supreme Court judges. Legislative power is in the hands of Congress, consisting of two chambers elected by direct suffrage: the House of Representatives, with 435 members elected for 2 years in a number proportional to the population of the single states (each state having at least one representative); and the Senate, with 100 members, 2 for each state, elected for 6 years, a third being renewed every 2 years. The Senate has wide responsibilities in foreign policy and exclusive competence for the ratification of international treaties.

Defence.
The United States Armed Forces include Army, Navy, Air Force and Marine Corps, and Coast Guard. They are present in every strategic point of the planet and constitute the backbone of NATO forces. The quota of female personnel is around 15% of the total. The US government does not recognize the jurisdiction of the International Criminal Court (ICC) in The Hague and has signed bilateral treaties with various countries to prevent USA military personnel from being tried locally for crimes committed overseas.
The United States is a nuclear power and exercises great vigilance over the potential spread of atomic weapons in countries which it does not consider reliable, such as North Korea or Iran. Although, in 2002, the country withdrew unilaterally from the Anti-ballistic Missile Treaty signed with the USSR in 1972, in 2010, the administration signed an agreement with Russia to reduce strategic nuclear weapons.

Justice.
The legal system is based on English Common Law. The highest organ is the Supreme Court (9 members appointed for life by the President), which rules on the constitutionality of laws passed by Congress and re-examines cases referred from federal courts. The prison population is the highest in the world (about 2.3 million prisoners in 2018). With a ruling of 1 March 2005, the Supreme Court abolished the death penalty for those who were under 18 years of age at the time the crime was committed.

Population by age and gender (% - 2017)
	75+ 60-74 45-59 30-44 15-29 0-14
MALE	AGE	FEMALE

In 2006 the country population passed the threshold of 300 million. Overall, demographic growth is higher than the European average, though there are significant differences (in fertility, death rate etc.) between various areas and between communities: the rate of natural increase, which among whites is close to zero, is high among blacks, Asians and Latino Americans. There are high numbers of immigrants, almost 50% of them coming from Latin America (Mexico in particular).

Economic situation.
As promised during his electoral campaign, D. Trump approved (20 December 2017) an extensive fiscal reform that reduced, from 35% to 21%, taxes on company profits and earnings of individuals, particularly those of the upper classes. The drop in revenue, however, contributed to an increase in the public debt. The growth of the GDP in 2018 carried on the positive trend seen in 2017, and unemployment continued to fall, reaching levels not seen since before the 2007-08 financial crisis.

Primary sector
Agriculture.
Farming is highly productive, at the forefront in applying the most up-to-date techniques such as biotechnology. Much of the arable land is cultivated with cereals, the main ones being maize (Iowa, Illinois, Nebraska, Minnesota and Indiana), also used to produce ethanol for motor fuel, and wheat (Kansas, North Dakota, Montana, Minnesota and South Dakota) and barley (Idaho, Montana, North Dakota). Other important crops are cotton (above all in Texas, but also California and Georgia), soya beans (Illinois, Iowa, Minnesota, Indiana, Nebraska and Ohio), flax, peanuts (Georgia), sunflower seeds (North Dakota), tobacco (North Carolina, Kentucky). For the production of sugar there are plantations of both sugar cane (Florida and Louisiana) and sugar beet (Minnesota, Idaho and North Dakota). The cultivation of fruit and citrus fruit is widespread (in Florida, California, Arizona and Texas); as well as that of vegetables (California); the growing of vines for wine production is increasing (California).
Forests.
The northern slopes of the Pacific are thickly wooded (Tacoma is the timber capital); Florida and the neighbouring parts of the Gulf of Mexico are renowned for pitch pine (Pinus rigida), exported from Pensacola. Timber, 55% of it from conifers, supplies a flourishing furniture industry, principally located along the Atlantic seaboard, with its main centres in New York, Grand Rapids (Mi.), Evansville (In.), Chicago and Rockford (Il.); the wood pulp and paper industries are also significant.
Livestock.
Cattle, pigs and poultry are all important, farmed both industrially and extensively on the vast prairies of the Midwest and in the region of the Rocky Mountains. The dairy industry is mainly concentrated in the north-eastern states (the Dairy Belt).
Fishing.
The USA is among the world’s greatest producers of fish in terms of catch. In Chesapeake Bay, Long Island Sound, on the coast of the Gulf of Mexico and in San Francisco Bay there are shellfish farms (crustaceans and molluscs). The main fishing ports are San Pedro (Ca.), Pascagoula-Moss Point (Ms.), Cameron, Empire (La.), Reedville (Va.), Beaufort-Morehead City (N.C.), New Bedford (Ma.).

Secondary sector
Minerals.
Mineral resources are vast and diversified. The most important of the coalfields extends along the internal slopes of the Appalachian Mountains, from Pennsylvania to Alabama; other important deposits are in the central coalfield, between mid-Mississippi and lower Ohio, and west of the Mississippi, from Texas to Iowa (which produce bituminous coal), as well as those in the Rocky Mountains (lignite). Even more important than coal is oil, the best deposits being found in Texas, Gulf of Mexico, North Dakota, California, Alaska and Oklahoma.
An extensive network of oil pipelines carries the crude oil to refineries. The oilfields are also rich sources of natural gas; the largest deposits are found in Texas, Pennsylvania, Oklahoma, Wyoming and Louisiana. Since the beginning of the twenty-first century, shale gas reserves have continued to grow in importance, constituting almost one-third of national production; the main reserves are in Louisiana, Ohio, Pennsylvania, Texas and West Virginia.
The biggest iron ore deposits are to be found close to Lake Superior, in the eastern states, in Texas, Missouri, Colorado, Utah, New Mexico, Wyoming and Nevada. The most important copper deposits are in Arizona, Utah, Montana, New Mexico and Nevada. Lead mainly comes from Missouri, Idaho, Utah and Colorado.
Zinc is chiefly mined in Tennessee, Idaho and Colorado. In Arkansas (Bauxite), Georgia (Adairsville) and Alabama (Eufaula) bauxite is mined. Mercury comes from mines in California, Nevada and Idaho.
Gold is widespread in South Dakota, Utah, Nevada and Arizona; silver is mainly found in Idaho, Arizona (in association with gold deposits), Montana and Utah.
The USA is among the largest producers of molybdenum (Colorado and New Mexico); there are also widespread deposits of vanadium (Colorado), tungsten (Idaho, Colorado, California), and zirconium. Uranium is mined in particular in Wyoming, Nebraska, New Mexico, Arizona, Colorado, Utah and Texas; caesium in Maine; thorium in New Hampshire, Idaho and Montana. Sulfur comes from Texas, Louisiana, California and Nevada. The production of phosphate rock is also important (in Florida, Idaho, Tennessee, Montana and Wyoming); potash comes principally from New Mexico, California, Utah and Michigan.
Energy.
Most of the electricity produced is derived from fossil fuels.
The amount of hydro-electric power generated, although limited in percentage terms, is one of the largest in the world in absolute terms; the principal hydro-electric plants are in Bath County, Chief Joseph (Virginia), Castaic (California), Grand Coulee (Washington), Hoover (Arizona/Nevada), John Day (Oregon/Washington), Robert Moses-Niagara (New York) and The Dalles (Oregon).
There are 99 nuclear reactors in operation (with 2 more under construction), providing around 20% of the electricity output in the country; the principal nuclear power stations are: Palo Verde, South Texas, Grand Gulf, Susquehanna, Nine Mile Point, Perry, Seabrook, Mola, Wolf Creek, Callaway, Comanche Peak, Salem, Waterford, Braidwood, Byron, Hope Creek, Vogtle, Sequoyah, Watts Bar, LaSalle County. The new Obama administration has taken measures to support the development of sources of renewable energy (solar, wind power), with the additional aim of assisting industrial recovery.
Industry.
In the iron and steel industry, the blast furnaces are almost all situated in the eastern part of the country (Pennsylvania, Indiana, Ohio and Illinois). Additionally, the favourable position for the supply of iron ore gave rise to the development of steelworks in lake ports (such as Detroit-Toledo, Lorain, Cleveland, Erie and Chicago). Imported iron ore supplies the steelworks in Sparrows Point (Md.), Morrisville (N.C.) and Bethlehem (Pa.). Important products of the metallurgical industry are aluminium, copper, lead, tin, zinc and magnesium. Major oil refineries are found in practically all the states. Cement is mainly produced in California, Pennsylvania and Texas. The principal centres for mechanical industry are Philadelphia, Worcester, Pittsburgh, Chicago, Hartford, Dayton, Schenectady and Syracuse. The main centre of the motor industry is Detroit, where Ford, FCA (ex Chrysler) and General Motors are headquartered; the sector was badly hit by the economic crisis, which led to the bankruptcy of Chrysler (partly bought out by Fiat in 2009) and to a process of profound reorganization and state support.
The country is home to a number of factories of various European and Japanese motor companies. The aeronautical industry is highly developed, concentrated along the Pacific seaboard (Seattle, Los Angeles, Santa Ana, San Jose and San Diego). The shipbuilding industry operates large shipyards along the coastlines and on the Great Lakes.
Among the textile industries, cotton predominates, with centres from Alabama to Maine. Artificial textile fibres are produced in Massachusetts and Rhode Island; the USA is also among the world’s largest producer of synthetic fibres. New York, Troy, Baltimore and Chicago are the principal centres of the clothing industry. Hollywood is the most important centre of the film industry. A decisive role is played by the sectors with a high technological content, such as aerospace, electronics, IT, telecommunications, fine chemicals and biotechnology. Production centres have close ties with universities and research institutes: the most important are the Silicon Valley (near San Francisco), the technology centres of the east coast, from Boston to Raleigh, and those of the Sun Belt, from Texas to Arizona and New Mexico.

Tertiary sector
Foreign trade.
The trade balance has been at a significant deficit for decades.

Main exports (M US$ - 2017) machinery 171 199, aircraft & spacecraft and parts thereof 131 169, electrical and electronic equipment 102 115, technical and electro-medical appliances 83 555, petroleum products 82 227, vehicles and parts thereof 76 516, chemicals 76 265, plastics 61 503, cars 53 581, pharmaceuticals 45 053, electronic integrated circuits 38 125, iron and steel 34 477, telecommunications equipment 34 006, computers and accessories 30 455, natural gas 22 266, crude oil 21 825, soya beans 21 658, jewels and precious stones 21 590, gold 19 824, fruit and vegetables 19 655, diamonds 18 995, wheat and other cereals 18 688, meat 16 398, paper and paperboard 15 763

Finance
and banking.
Central bank functions are carried out by the Federal Reserve System, set up in 1913.
New York is home to the world’s leading commercial banks, the Wall Street stock market (NYSE), the largest in the world, and NASDAQ (National Association of Securities Dealers Automated Quotations), the market for technology stocks. Chicago hosts the biggest commodities market in the world.

Tourism. The USA is one of the most important world’s tourist destinations. Popular places are New York, the national parks, the beaches (Florida and California).

Transport.
The network of highways and motorways is among the most extensive in the world. The railways are completely private and do not offer an effective passenger service, other than for commuters living around major conurbations. Numerous plans for high-speed railway lines are being researched in California, between San Francisco and Los Angeles, and between the main cities on the Eastern coast. The internal waterways consist of two major interconnected systems: the Great Lakes and the Mississippi waterways.

Media and telecommunication.
There are two public radio and television broadcasters (NPR and PBS), in addition to a number of private commercial networks, among them ABC (American Broadcasting Co.), NBC (National Broadcasting Co.), CBS (Columbia Broadcasting System), CNN (Cable News Network) and Fox (Fox Broadcasting Co.).

Education and research.
Compulsory education lasts 9 years and is divided into two phases: elementary (6 years) and secondary; secondary education includes two levels: Junior High School (3 years), which completes compulsory education, and Senior High School (3 years), in which students can choose between three courses of study (academic, vocational and general). There is a choice between free public schools and fee-charging private schools. Higher education is provided in colleges, with four-year courses leading to a diploma (in science or humanities), and universities, which envisage undergraduate college, post-graduate specialization schools and schools of higher professional training.

Social security.
Social assistance is provided through various federally-funded programs, in addition to others within the individual states. Specific social security programs are handled by different bodies, in particular by the Social Security Administration (pensions, disability benefit etc.).

Health.
Over 64% of the workforce depend on health maintenance organizations, the intermediaries that control private health; 17% are insured by Medicare (the national programme for the elderly); 20% by Medicaid (the programme for those on low incomes); 9% have no health cover. In 2014, the extension of health cover was completed to approximately 13 million citizens who were previously not covered.