Virginia the Commonwealth of Virginia, is a state in the Southeastern and Mid-Atlantic regions of the United States located between the Atlantic Coast and the Appalachian Mountains. Virginia is nicknamed the "Old Dominion" due to its status as the first English colonial possession established in mainland North America and "Mother of Presidents" because eight U. S. presidents were born there, more than any other state. The geography and climate of the Commonwealth are shaped by the Blue Ridge Mountains and the Chesapeake Bay, which provide habitat for much of its flora and fauna; the capital of the Commonwealth is Richmond. The Commonwealth's estimated population as of 2018 is over 8.5 million. The area's history begins with several indigenous groups, including the Powhatan. In 1607 the London Company established the Colony of Virginia as the first permanent New World English colony. Slave labor and the land acquired from displaced Native American tribes each played a significant role in the colony's early politics and plantation economy.
Virginia was one of the 13 Colonies in the American Revolution. In the American Civil War, Virginia's Secession Convention resolved to join the Confederacy, Virginia's First Wheeling Convention resolved to remain in the Union. Although the Commonwealth was under one-party rule for nearly a century following Reconstruction, both major national parties are competitive in modern Virginia; the Virginia General Assembly is the oldest continuous law-making body in the New World. The state government was ranked most effective by the Pew Center on the States in both 2005 and 2008, it is unique in how it treats cities and counties manages local roads, prohibits its governors from serving consecutive terms. Virginia's economy has many sectors: agriculture in the Shenandoah Valley. S. Department of Defense and Central Intelligence Agency. Virginia has a total area of 42,774.2 square miles, including 3,180.13 square miles of water, making it the 35th-largest state by area. Virginia is bordered by Maryland and Washington, D.
C. to the north and east. Virginia's boundary with Maryland and Washington, D. C. extends to the low-water mark of the south shore of the Potomac River. The southern border is defined as the 36° 30′ parallel north, though surveyor error led to deviations of as much as three arcminutes; the border with Tennessee was not settled until 1893, when their dispute was brought to the U. S. Supreme Court; the Chesapeake Bay separates the contiguous portion of the Commonwealth from the two-county peninsula of Virginia's Eastern Shore. The bay was formed from the drowned river valleys of the James River. Many of Virginia's rivers flow into the Chesapeake Bay, including the Potomac, Rappahannock and James, which create three peninsulas in the bay; the Tidewater is a coastal plain between the fall line. It includes major estuaries of Chesapeake Bay; the Piedmont is a series of sedimentary and igneous rock-based foothills east of the mountains which were formed in the Mesozoic era. The region, known for its heavy clay soil, includes the Southwest Mountains around Charlottesville.
The Blue Ridge Mountains are a physiographic province of the Appalachian Mountains with the highest points in the state, the tallest being Mount Rogers at 5,729 feet. The Ridge and Valley region includes the Great Appalachian Valley; the region includes Massanutten Mountain. The Cumberland Plateau and the Cumberland Mountains are in the southwest corner of Virginia, south of the Allegheny Plateau. In this region, rivers flow northwest, into the Ohio River basin; the Virginia Seismic Zone has not had a history of regular earthquake activity. Earthquakes are above 4.5 in magnitude, because Virginia is located away from the edges of the North American Plate. The largest earthquake, at an estimated 5.9 magnitude, was in 1897 near Blacksburg. A 5.8 magnitude earthquake struck central Virginia on August 2011, near Mineral. The earthquake was felt as far away as Toronto and Florida. 35 million years ago, a bolide impacted. The resulting Chesapeake Bay impact crater may explain what earthquakes and subsidence the region does experience.
Coal mining takes place in the three mountainous regions at 45 distinct coal beds near Mesozoic basins. Over 64 million tons of other non-fuel resources, such as slate, sand, or gravel, were mined in Virginia in 2018; the state's carbonate rock is filled with more than 4,000 caves, ten of which are open for tourism, including the popular Luray Caverns and Skyline Caverns. The climate of Virginia is humid subtropical and becomes warmer and more humid farther south and east. Seasonal extremes vary from average lows of 26 °F in January to average highs of 86 °F in July; the Atlantic Ocean has a strong effect on southeastern coastal areas of the state. Influenced by the Gulf Stream, coastal weather is subject to hurricanes, most pronouncedly near the mouth of Chesapeake Bay. In spite of its position adjacent to the Atlantic Ocean the coastal areas have a significant continental influence with quite large temperature differences between summ
Indigo is a deep and rich color close to the color wheel blue, as well as to some variants of ultramarine. It is traditionally regarded as a color in the visible spectrum, as well as one of the seven colors of the rainbow: the color between violet and blue; the color indigo is named after the indigo dye derived from the plant Indigofera tinctoria and related species. The first known recorded use of indigo as a color name in English was in 1289. Species of Indigofera were cultivated in East Asia, Egypt and Peru in antiquity; the earliest direct evidence for the use of indigo dates to around 4000 BC and comes from Huaca Prieta, in contemporary Peru. Pliny the Elder mentions India as the source of the dye, it was imported from there in small quantities via the Silk Road. The Ancient Greek term for the dye was Ἰνδικὸν φάρμακον, adopted to Latin as indicum and via Portuguese gave rise to the modern word indigo. Spanish explorers discovered an American species of indigo and began to cultivate the product in Guatemala.
The English and French subsequently began to encourage indigo cultivation in their colonies in the West Indies. Blue dye can be made from two different types of plants: the indigo plant, which produces the best results, from the woad plant Isatis tinctoria known as pastel. For a long time woad was the main source of blue dye in Europe. Woad was replaced by true indigo as trade routes opened up, both plant sources have now been replaced by synthetic dyes; the Early Modern English word indigo referred to the dye, not to the color itself, indigo is not traditionally part of the basic color-naming system. Modern sources place indigo in the electromagnetic spectrum between 420 and 450 nanometers, which lies on the short-wave side of color wheel blue, towards violet. However, the correspondence of this definition with colors of actual indigo dyes is disputed. Optical scientists Hardy and Perrin list indigo as between 445 and 464 nm wavelength, which occupies a spectrum segment from the color wheel blue extending to the long-wave side, towards azure.
Isaac Newton introduced indigo as one of the seven base colors of his work. In the mid-1660s, when Newton bought a pair of prisms at a fair near Cambridge, the East India Company had begun importing indigo dye into England, supplanting the homegrown woad as source of blue dye. In a pivotal experiment in the history of optics, the young Newton shone a narrow beam of sunlight through a prism to produce a rainbow-like band of colors on the wall. In describing this optical spectrum, Newton acknowledged that the spectrum had a continuum of colors, but named seven: "The originall or primary colours are Red, Green, Blew, & a violet purple, he linked the seven prismatic colors to the seven notes of a western major scale, as shown in his color wheel, with orange and indigo as the semitones. Having decided upon seven colors, he asked a friend to divide up the spectrum, projected from the prism onto the wall: I desired a friend to draw with a pencil lines cross the image, or pillar of colours, where every one of the seven aforenamed colours was most full and brisk, where he judged the truest confines of them to be, whilst I held the paper so, that the said image might fall within a certain compass marked on it.
And this I did because my own eyes are not critical in distinguishing colours because another, to whom I had not communicated my thoughts about this matter, could have nothing but his eyes to determine his fancy in making those marks. Indigo is therefore counted as one of the traditional colors of the rainbow, the order of, given by the mnemonic Roy G. Biv. James Clerk Maxwell and Hermann von Helmholtz accepted indigo as an appropriate name for the color flanking violet in the spectrum. Scientists conclude that Newton named the colors differently from current usage. According to Gary Waldman, "A careful reading of Newton's work indicates that the color he called indigo, we would call blue. If this is true, Newton's seven spectral colors would have been: Red: Orange: Yellow: Green: Blue: Indigo: Violet: The human eye does not differentiate hues in the wavelengths between what we today call blue and violet. If this is where Newton meant indigo to lie, most individuals would have difficulty distinguishing indigo from its neighbors.
According to Isaac Asimov, "It is customary to list indigo as a color lying between blue and violet, but it has never seemed to me that indigo is worth the dignity of being considered a separate color. To my eyes it seems deep blue."Modern color scientists divide the spectrum between violet and blue at about 450 nm, with no indigo. Like many other colors, indigo gets its name from an object in the natural world—the plant named indigo once used for dyeing cloth; the color electric indigo is a saturated color between the traditional indigo and violet. This is the brightest color indigo; the web color blue violet or deep indigo is a tone of indigo brighter than pigment indigo, but not as bright as electric indigo. The color pigment indigo is equivalent to the web color indigo and approximates the color indigo, reproduced in pigments and colored pencils; the color of indigo dye is
A public company, publicly traded company, publicly held company, publicly listed company, or public limited company is a corporation whose ownership is dispersed among the general public in many shares of stock which are traded on a stock exchange or in over the counter markets. In some jurisdictions, public companies over a certain size must be listed on an exchange. A public company can be unlisted. Public companies are formed within the legal systems of particular nations, therefore have national associations and formal designations which are distinct and separate. For example one of the main public company forms in the United States is called a limited liability company, in France is called a "society of limited responsibility", in Britain a public limited company, in Germany a company with limited liability. While the general idea of a public company may be similar, differences are meaningful, are at the core of international law disputes with regard to industry and trade. In the early modern period, the Dutch developed several financial instruments and helped lay the foundations of modern financial system.
The Dutch East India Company became the first company in history to issue bonds and shares of stock to the general public. In other words, the VOC was the first publicly traded company, because it was the first company to be actually listed on an official stock exchange. While the Italian city-states produced the first transferable government bonds, they did not develop the other ingredient necessary to produce a fledged capital market: corporate shareholders; as Edward Stringham notes, "companies with transferable shares date back to classical Rome, but these were not enduring endeavors and no considerable secondary market existed." The securities of a publicly traded company are owned by many investors while the shares of a held company are owned by few shareholders. A company with many shareholders is not a publicly traded company. In the United States, in some instances, companies with over 500 shareholders may be required to report under the Securities Exchange Act of 1934. Public companies possess some advantages over held businesses.
Publicly traded companies are able to raise funds and capital through the sale of shares of stock. This is the reason publicly traded corporations are important; the profit on stock is gained in form of capital gain to the holders. The financial media and the public are able to access additional information about the business, since the business is legally bound, motivated, to publicly disseminate information regarding the financial status and future of the company to its many shareholders and the government; because many people have a vested interest in the company's success, the company may be more popular or recognizable than a private company. The initial shareholders of the company are able to share risk by selling shares to the public. If one were to hold a 100% share of the company, he or she would have to pay all of the business's debt; this increases asset liquidity and the company does not need to depend on funding from a bank. For example, in 2013 Facebook founder Mark Zuckerberg owned 29.3% of the company's class A shares, which gave him enough voting power to control the business, while allowing Facebook to raise capital from, distribute risk to, the remaining shareholders.
Facebook was a held company prior to its initial public offering in 2012. If some shares are given to managers or other employees, potential conflicts of interest between employees and shareholders will be remitted; as an example, in many tech companies, entry-level software engineers are given stock in the company upon being hired. Therefore, the engineers have a vested interest in the company succeeding financially, are incentivized to work harder and more diligently to ensure that success. Many stock exchanges require that publicly traded companies have their accounts audited by outside auditors, publish the accounts to their shareholders. Besides the cost, this may make useful information available to competitors. Various other annual and quarterly reports are required by law. In the United States, the Sarbanes–Oxley Act imposes additional requirements; the requirement for audited books is not imposed by the exchange known as OTC Pink. The shares may be maliciously held by outside shareholders and the original founders or owners may lose benefits and control.
The principal-agent problem, or the agency problem is a key weakness of public companies. The separation of a company's ownership and control is prevalent in such countries as U. K and U. S. In the United States, the Securities and Exchange Commission requires that firms whose stock is traded publicly report their major shareholders each year; the reports identify all institutional shareholders, all company officials who own shares in their firm, any individual or institution owning more than 5% of the firm's stock. For many years, newly created companies were held but held initial
Airline hubs or hub airports are used by one or more airlines to concentrate passenger traffic and flight operations at a given airport. They serve, it is part of the hub-and-spoke system. An airline operates flights from several non-hub cities to the hub airport, passengers traveling between spoke cities need to connect through the hub; this paradigm creates economies of scale that allow an airline to serve city-pairs that could otherwise not be economically served on a non-stop basis. This system contrasts with the point-to-point model, in which there are no hubs and nonstop flights are instead offered between spoke cities. Hub airports serve origin and destination traffic. In the airline industry, a focus city is a destination from which an airline operates limited point-to-point routes. Ergo, a focus city caters to the local market rather than to connecting passengers. However, with the term's expanded usage, a focus city may function as a small-scale or total hub. Allegiant Air, JetBlue and Southwest Airlines are examples of US-based airlines that consider some of their focus cities run like a hub.
The hub-and-spoke system allows an airline to serve fewer routes, so fewer aircraft are needed. The system increases passenger loads. However, the system is costly. Additional employees and facilities are needed to cater to connecting passengers. To serve spoke cities of varying populations and demand, an airline requires several aircraft types, specific training and equipment are necessary for each type. In addition, airlines may experience capacity constraints. For the passenger, the hub-and-spoke system offers one-stop air service to a wide array of destinations. However, it requires having to make connections en route to their final destination, which increases travel time. Additionally, airlines can come to monopolise their hubs, allowing them to increase fares as passengers have no alternative. Airlines may operate banks of flights at their hubs, in which several flights arrive and depart within short periods of time; the banks may be known as "peaks" of activity at the hubs and the non-banks as "valleys".
Banking allows for short connection times for passengers. However, an airline must assemble a large number of resources to cater to the influx of flights during a bank, having several aircraft on the ground at the same time can lead to congestion and delays. In addition, banking could result in inefficient aircraft utilisation, with aircraft waiting at spoke cities for the next bank. Instead, some airlines have debanked their hubs, introducing a "rolling hub" in which flight arrivals and departures are spread throughout the day; this phenomenon is known as "depeaking". While costs may decrease, connection times are longer at a rolling hub. American Airlines was the first to depeak its hubs, trying to improve profitability following the September 11 attacks, it rebanked its hubs in 2015, feeling the gain in connecting passengers would outweigh the rise in costs. The hub-and-spoke system is used by some cargo airlines. FedEx Express established its main hub in Memphis in 1973, prior to the deregulation of the air cargo industry in the United States.
The system has created an efficient delivery system for the airline. Other airlines that use this system include UPS Airlines, TNT Airways, Cargolux and DHL Aviation, which operate their primary hubs at Louisville, Liège, Luxembourg and Leipzig respectively. Although the term focus city is used to refer to an airport from which an airline operates limited point-to-point routes, its usage has loosely expanded to refer to a small-scale hub as well. For example, JetBlue's New York–JFK focus city runs like a hub, although in reality it is still deemed as a focus city. A fortress hub exists when an airline controls a significant majority of the market at one of its hubs. Competition is difficult at fortress hubs. Examples include Delta hubs at Atlanta, Salt Lake City and Minneapolis–Saint Paul. Flag carriers have enjoyed similar dominance at the main international airport of their countries and some still do. Examples include Lufthansa at Frankfurt Airport, Air Canada at Toronto Pearson Airport, Alitalia at Rome Fiumicino Airport, KLM at Amsterdam Airport Schiphol, Garuda Indonesia at Soekarno-Hatta International Airport, British Airways at London Heathrow, Air China at Beijing Capital Airport, Iberia at Madrid-Barajas Airport and Air France at Paris Orly and Charles de Gaulle Airports.
A primary hub is the main hub for an airline. However, as an airline expands operations at its primary hub to the point that it experiences capacity limitations, it may elect to open secondary hubs. Examples of such hubs are Turkish Airlines' Istanbul–Sabiha Gökçen hub, British Airways' hub at London-Gatwick, Air India's hub at Mumbai and Lufthansa's hub at Munich. By operating multiple hubs, airlines can expand their geographic reach, they can better serve spoke–spoke markets, providing more itineraries with connections at different hubs. A given hub's capacity may become exhausted or capacity shortages may occur during peak periods of the day, at which point airlines may be compelled to shift traffic to a reliever hub. A reliever hub has the potential to serve several functions for an airline: it can bypass the congested hub, it can absorb
Chief executive officer
The chief executive officer or just chief executive, is the most senior corporate, executive, or administrative officer in charge of managing an organization – an independent legal entity such as a company or nonprofit institution. CEOs lead a range of organizations, including public and private corporations, non-profit organizations and some government organizations; the CEO of a corporation or company reports to the board of directors and is charged with maximizing the value of the entity, which may include maximizing the share price, market share, revenues or another element. In the non-profit and government sector, CEOs aim at achieving outcomes related to the organization's mission, such as reducing poverty, increasing literacy, etc. In the early 21st century, top executives had technical degrees in science, engineering or law; the responsibility of an organization's CEO are set by the organization's board of directors or other authority, depending on the organization's legal structure.
They can be far-reaching or quite limited and are enshrined in a formal delegation of authority. Responsibilities include being a decision maker on strategy and other key policy issues, leader and executor; the communicator role can involve speaking to the press and the rest of the outside world, as well as to the organization's management and employees. As a leader of the company, the CEO or MD advises the board of directors, motivates employees, drives change within the organization; as a manager, the CEO/MD presides over the organization's day-to-day operations. The term refers to the person who makes all the key decisions regarding the company, which includes all sectors and fields of the business, including operations, business development, human resources, etc; the CEO of a company is not the owner of the company. In some countries, there is a dual board system with two separate boards, one executive board for the day-to-day business and one supervisory board for control purposes. In these countries, the CEO presides over the executive board and the chairman presides over the supervisory board, these two roles will always be held by different people.
This ensures a distinction between management by the executive board and governance by the supervisory board. This allows for clear lines of authority; the aim is to prevent a conflict of interest and too much power being concentrated in the hands of one person. In the United States, the board of directors is equivalent to the supervisory board, while the executive board may be known as the executive committee. In the United States, in business, the executive officers are the top officers of a corporation, the chief executive officer being the best-known type; the definition varies. In the case of a sole proprietorship, an executive officer is the sole proprietor. In the case of a partnership, an executive officer is a managing partner, senior partner, or administrative partner. In the case of a limited liability company, executive officer is any manager, or officer. A CEO has several subordinate executives, each of whom has specific functional responsibilities referred to as senior executives, executive officers or corporate officers.
Subordinate executives are given different titles in different organizations, but one common category of subordinate executive, if the CEO is the president, is the vice-president. An organization may have more than one vice-president, each tasked with a different area of responsibility; some organizations have subordinate executive officers who have the word chief in their job title, such as chief operating officer, chief financial officer and chief technology officer. The public relations-focused position of chief reputation officer is sometimes included as one such subordinate executive officer, but, as suggested by Anthony Johndrow, CEO of Reputation Economy Advisors, it can be seen as "simply another way to add emphasis to the role of a modern-day CEO – where they are both the external face of, the driving force behind, an organisation culture". In the US, the term chief executive officer is used in business, whereas the term executive director is used in the not-for-profit sector; these terms are mutually exclusive and refer to distinct legal duties and responsibilities.
Implicit in the use of these titles, is that the public not be misled and the general standard regarding their use be applied. In the UK, chief executive and chief executive officer are used in both business and the charitable sector; as of 2013, the use of the term director for senior charity staff is deprecated to avoid confusion with the legal duties and responsibilities associated with being a charity director or trustee, which are non-executive roles. In the United Kingdom, the term director is used instead of chief officer". Business publicists since the days of Edward Bernays and his client John D. Rockefeller and more the corporate publicists for Henry Ford, promoted the concept of the "celebrity CEO". Business journalists have adopted this approach, which assumes that the corporate achievements in the arena of manufacturing, wer
Airbus A320neo family
The Airbus A320neo family is a development of the A320 family of narrow-body airliners produced by Airbus. The original family has been renamed A320ceo, for current engine option. Launched on 1 December 2010, it made its first flight on 25 September 2014 and it was introduced by Lufthansa on 25 January 2016. Re-engined with CFM International LEAP-1A or Pratt & Whitney PW1000G engines and with large sharklets, it should be 15% more fuel efficient; the A320neo family is based on the previous A319, A320 and A321. As of February 2019, Airbus has delivered 687 aircraft. In 2006 Airbus started the A320 Enhanced programme as a series of improvements targeting a 4–5% efficiency gain with large winglets, aerodynamic refinements, weight savings and a new aircraft cabin. At the time Airbus' Sales Chief John Leahy said "Who's going to roll over a fleet to a new generation aircraft for 5% better than an A320 today? If another 10% improvement might be coming in the second half of the next decade based on new engine technology".
Airbus launched the sharklet blended wingtip device during the November 2009 Dubai Airshow. The installation offers a 3.5 % fuel burn reduction on flights over 2,800 km. At the February 2010 Singapore Air Show, Airbus said its decision to launch was scheduled for the July 2010 Farnborough Air Show; the decision had still not been taken by August, but the engine choice included the CFM International LEAP-1A and the Pratt & Whitney PW1000G, with 20% lower maintenance cost than current A320 engines. The new engines burn 16% less fuel, though the actual gain is less as 1–2% is lost when installed on an existing aircraft. On 1 December 2010, Airbus launched the A320neo "New Engine Option' with 500 nmi more range or 2 t more payload, planned to deliver 4,000 over 15 years. Development costs were predicted to be "slightly more than €1 billion "; the neo list price would be $6 million more than the ceo, including $3.5 million for airframe modifications and around $0.9 million for the sharklets. The A320neo was slated for service entry in spring 2016, the A321neo six months and the A319neo six months after that.
The 2010 order for 40 Bombardier CS300s and 40 options from Republic Airways Holdings – owner of exclusive A319/320 operator Frontier Airlines – pushed Airbus into the re-engine. Airbus COO-customers John Leahy decided against ignoring the CSeries and allowing it to grow, as Boeing had done with Airbus, instead aggressively competed against Bombardier Aerospace. Introduction was advanced to October 2015. Airbus announces a 15% fuel saving thanks to those latest-generation engines and large sharklet wingtip devices, keeping over 95% airframe commonality with the current A320, its commonality helped to reduce delays associated with large changes. In March 2013, airlines' choices between the two engines were equal; the new "Space-Flex" optional cabin configuration increases space-efficiency with a new rear galley configuration and a "Smart-Lav" modular lavatory design – allowing an in-flight change of two lavatories into one accessible toilet. The rearranged cabin allows up to 20 more passengers for the A321neo without "putting more sardines in the can" with the larger "Cabin-Flex" modified exits described below.
Total fuel consumption per seat is reduced by over 20%, while the rearranged cabin allows up to nine more passengers for the A320neo. The first Airbus A320neo rolled out of the Toulouse factory on 1 July 2014 and first flight was scheduled for September 2014; the first flight of the neo occurred on 25 September 2014. Its Pratt & Whitney PW1100G-JM geared turbofan engine was certified by the Federal Aviation Administration on 19 December 2014. After 36 months, the A320neo and A321neo had flown around 4,000 hours for certification of the two powerplant versions; this is about three-quarters of the certification effort of a new design. Of these 4,000 hours flown, 2,250 were with 1,770 with CFM LEAPs; the flight test programme was to conclude in 2018 with the completion of A319neo testing. The changes impact flying qualities and system integration; the neo is 1.8 t heavier than the ceo, but take-off and landing performance is the same with a modified rotation law, adjusted wing flap and wing slat angles and rudder deflection increased by 5° to cope with the higher thrust.
The A320neo is half as loud as an A320 at take-off, with an 85 decibel noise footprint. The LEAP-powered A321neo has 83.3 dB flyover noise lower than the older CFM56 and V2500. First delivery slipped to early 2016. Lufthansa took delivery of the first A320neo on 20 January 2016. Two hundred deliveries were targeted in 2017, but as Pratt & Whitney faced ramp-up difficulties, Airbus expected that 30 aircraft would have to be parked awaiting engines; the fourth and latest final assembly line in Hamburg was to open in July 2017. With 90 A320neos delivered by October 2017, Airbus acknowledged that it would not attain the 200 target with many deliveries in the fourth quarter: more than 40 A320neos are parked without engines, but with most of the engine issues resolved by early 2018, more than half of the A320s delivered in 2018 were expected to be neos. Airbus expected to produce 60 narrow bodies per month by the middle of 2019, studied higher rates. Airbus confirmed plans to reach 63 monthly from 55 in 2018 and study 70 to 75 monthly beyond 2019, though Safran, one of the two partners in LEAP producer CFM, could
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti