Printed electronics is a set of printing methods used to create electrical devices on various substrates. Printing uses common printing equipment suitable for defining patterns on material, such as screen printing, gravure, offset lithography, inkjet. By electronic industry standards, these are low cost processes. Electrically functional electronic or optical inks are deposited on the substrate, creating active or passive devices, such as thin film transistors. Printed electronics is expected to facilitate widespread low-cost, low-performance electronics for applications such as flexible displays, smart labels and animated posters, active clothing that do not require high performance; the term printed electronics is related to organic electronics or plastic electronics, in which one or more inks are composed of carbon-based compounds. These other terms refer to the ink material, which can be deposited by solution-based, vacuum-based or other processes. Printed electronics, in contrast, specifies the process, subject to the specific requirements of the printing process selected, can utilize any solution-based material.
This includes organic semiconductors, inorganic semiconductors, metallic conductors and nanotubes. For the preparation of printed electronics nearly all industrial printing methods are employed. Similar to conventional printing, printed electronics applies ink layers one atop another. So the coherent development of printing methods and ink materials are the field's essential tasks; the most important benefit of printing is low-cost volume fabrication. The lower cost enables use in more applications. An example is RFID-systems, which enable contactless identification in transport. In some domains, such as light-emitting diodes printing does not impact performance. Printing on flexible substrates allows electronics to be placed on curved surfaces, for example, printing solar cells on vehicle roofs. More conventional semiconductors justify their much higher costs by providing much higher performance; the maximum required resolution of structures in conventional printing is determined by the human eye.
Feature sizes smaller than 20 µm cannot be distinguished by the human eye and exceed the capabilities of conventional printing processes. In contrast, higher resolution and smaller structures are necessary in much electronics printing, because they directly affect circuit density and functionality. A similar requirement holds for the precision with. Control of thickness and material compatibility are essential, but matter in conventional printing only if the eye can detect them. Conversely, the visual impression is irrelevant for printed electronics; the attraction of printing technology for the fabrication of electronics results from the possibility of preparing stacks of micro-structured layers in a much simpler and cost-effective way compared to conventional electronics. The ability to implement new or improved functionalities plays a role; the selection of the printing method used is determined by requirements concerning printed layers, by the properties of printed materials as well as economic and technical considerations of the final printed products.
Printing technologies divide between roll-to-roll-based approaches. Sheet-based inkjet and screen printing are best for high-precision work. Gravure and flexographic printing are more common for high-volume production, such as solar cells, reaching 10.000 square meters per hour. While offset and flexographic printing are used for inorganic and organic conductors, gravure printing is suitable for quality-sensitive layers like organic semiconductors and semiconductor/dielectric-interfaces in transistors, due to high layer quality. If high resolution is needed, gravure is suitable for inorganic and organic conductors. Organic field-effect transistors and integrated circuits can be prepared by means of mass-printing methods. Inkjets are flexible and versatile, can be set up with low effort. However, inkjets offer lower throughput of lower resolution, it is well suited for soluble materials like organic semiconductors. With high-viscosity materials, like organic dielectrics, dispersed particles, like inorganic metal inks, difficulties due to nozzle clogging occur.
Because ink is deposited via droplets and dispersion homogeneity is reduced. Using many nozzles and pre-structuring the substrate allows improvements in productivity and resolution, respectively. However, in the latter case non-printing methods must be employed for the actual patterning step. Inkjet printing is preferable for organic semiconductors in organic field-effect transistors and organic light-emitting diodes, but OFETs prepared by this method have been demonstrated. Frontplanes and backplanes of OLED-displays, integrated circuits, organic photovoltaic cells and other devices can be prepared with inkjets. Screen printing is appropriate for fabricating electrics and electronics due to its ability to produce patterned, thick layers from paste-like materials; this method can produce conducting lines from inorganic materials, but insulating and passivating layers, whereby layer thickness is more important than high resolution. Its 50 m²/h throughput and 100 µm resolution are similar to inkjets.
This versatile and co
A ticker symbol or stock symbol is an abbreviation used to uniquely identify publicly traded shares of a particular stock on a particular stock market. A stock symbol may consist of numbers or a combination of both. "Ticker symbol" refers to the symbols. Stock symbols are unique identifiers assigned to each security traded on a particular market. A stock symbol can consist of letters, numbers, or a combination of both, is a way to uniquely identify that stock; the symbols were kept as short as possible to reduce the number of characters that had to be printed on the ticker tape, to make it easy to recognize by traders and investors. The allocation of symbols and formatting convention is specific to each stock exchange. In the US, for example, stock tickers are between 1 and 4 letters and represent the company name where possible. For example, US-based computer company stock Apple Inc. traded on the NASDAQ exchange has the symbol AAPL, while the motor company Ford's stock, traded on the New York Stock Exchange has the single-letter ticker F.
In Europe, most exchanges use three-letter codes, for example Dutch consumer goods company Unilever traded on the Amsterdam Euronext exchange has the symbol UNA. While in Asia, numbers are used as stock tickers to avoid issues for international investors when using non-Latin scripts. For example, the bank HSBC's stock traded on the Hong Kong Stock Exchange has the ticker symbol 0005. Symbols sometimes change to reflect mergers. Prior to the 1999 merger with Mobil Oil, Exxon used a phonetic spelling of the company "XON" as its ticker symbol; the symbol of the firm after the merger was "XOM". Symbols are sometimes reused. In the US the single-letter symbols are sought after as vanity symbols. For example, since Mar 2008 Visa Inc. has used the symbol V, used by Vivendi which had delisted and given up the symbol. To qualify a stock, both the ticker and the exchange or country of listing needs to be known. On many systems both must be specified to uniquely identify the security; this is done by appending the location or exchange code to the ticker.
Although stock tickers identify a security, they are exchange dependent limited to stocks and can change. These limitations have led to the development of other codes in financial markets to identify securities for settlement purposes; the most prevalent of these is the International Securities Identifying Number. An ISIN uniquely identifies a security and its structure is defined in ISO 6166. Securities for which ISINs are issued include bonds, commercial paper and warrants; the ISIN code is a 12-character alpha-numerical code that does not contain information characterizing financial instruments, but serves for uniform identification of a security at trading and settlement. The ISIN identifies not the exchange on which it trades. For instance, Daimler AG stock trades on twenty-two different stock exchanges worldwide, is priced in five different currencies. ISIN cannot specify a particular trade in this case, another identifier the three- or four-letter exchange code will have to be specified in addition to the ISIN.
While a stock ticker identifies a security that can be traded, stock market indices are sometimes assigned a symbol though they can not be traded. Symbols for indices are distinguished by adding a symbol in front of the name, such as a caret or a dot. For example, Reuters lists the Nasdaq Composite index under the symbol. IXIC. In Canada the Toronto Stock Exchange TSX and the TSXV use the following special codes after the ticker symbol: In the United Kingdom, prior to 1996, stock codes were known as EPICs, named after the London Stock Exchange's Exchange Price Information Computer. Following the introduction of the Sequence trading platform in 1996, EPICs were renamed Tradable Instrument Display Mnemonics, but they are still referred to as EPICs. Stocks can be identified using their SEDOL number or their ISIN. In the United States, modern letter-only ticker symbols were developed by Standard & Poor's to bring a national standard to investing. A single company could have many different ticker symbols as they varied between the dozens of individual stock markets.
The term ticker refers to the noise made by the ticker tape machines once used by stock exchanges. The S&P system was standardized by the securities industry and modified as years passed. Stock symbols for preferred stock have not been standardized; some companies use a well-known product as their ticker symbol. Belgian brewer InBev, the brewer of Budweiser beer, uses "BUD" as its three-letter ticker for American Depository Receipts, symbolizing its premier product in the United States, its rival, Molson Coors Brewing Company, uses a beer-related symbol, "TAP". Southwest Airlines pays tribute to its headquarters at Love Field in Dallas through its "LUV" symbol. Cedar Fair Entertainment Company, which operates large amusement parks in the United States, uses "FUN" as its symbol. Harley-Davidson uses "HOG" for its Harley Owners Group. Yamana Gold uses "AUY", because on the periodic table of elements. Sotheby's uses the symbol "BID". While most symbols come from the company's name, sometimes it happens the other way around.
Tricon Global, owner of KFC, Pi
Ohio is a Midwestern state in the Great Lakes region of the United States. Of the fifty states, it is the 34th largest by area, the seventh most populous, the tenth most densely populated; the state's capital and largest city is Columbus. The state takes its name from the Ohio River, whose name in turn originated from the Seneca word ohiːyo', meaning "good river", "great river" or "large creek". Partitioned from the Northwest Territory, Ohio was the 17th state admitted to the Union on March 1, 1803, the first under the Northwest Ordinance. Ohio is known as the "Buckeye State" after its Ohio buckeye trees, Ohioans are known as "Buckeyes". Ohio rose from the wilderness of Ohio Country west of Appalachia in colonial times through the Northwest Indian Wars as part of the Northwest Territory in the early frontier, to become the first non-colonial free state admitted to the union, to an industrial powerhouse in the 20th century before transmogrifying to a more information and service based economy in the 21st.
The government of Ohio is composed of the executive branch, led by the Governor. Ohio occupies 16 seats in the United States House of Representatives. Ohio is known for its status as both a bellwether in national elections. Six Presidents of the United States have been elected. Ohio is an industrial state, ranking 8th out of 50 states in GDP, is the second largest producer of automobiles behind Michigan. Ohio's geographic location has proven to be an asset for economic expansion; because Ohio links the Northeast to the Midwest, much cargo and business traffic passes through its borders along its well-developed highways. Ohio has the nation's 10th largest highway network and is within a one-day drive of 50% of North America's population and 70% of North America's manufacturing capacity. To the north, Lake Erie gives Ohio 312 miles of coastline. Ohio's southern border is defined by the Ohio River, much of the northern border is defined by Lake Erie. Ohio's neighbors are Pennsylvania to the east, Michigan to the northwest, Lake Erie to the north, Indiana to the west, Kentucky on the south, West Virginia on the southeast.
Ohio's borders were defined by metes and bounds in the Enabling Act of 1802 as follows: Bounded on the east by the Pennsylvania line, on the south by the Ohio River, to the mouth of the Great Miami River, on the west by the line drawn due north from the mouth of the Great Miami aforesaid, on the north by an east and west line drawn through the southerly extreme of Lake Michigan, running east after intersecting the due north line aforesaid, from the mouth of the Great Miami until it shall intersect Lake Erie or the territorial line, thence with the same through Lake Erie to the Pennsylvania line aforesaid. Ohio is bounded by the Ohio River, but nearly all of the river itself belongs to Kentucky and West Virginia. In 1980, the U. S. Supreme Court held that, based on the wording of the cessation of territory by Virginia, the boundary between Ohio and Kentucky is the northern low-water mark of the river as it existed in 1792. Ohio has only that portion of the river between the river's 1792 low-water mark and the present high-water mark.
The border with Michigan has changed, as a result of the Toledo War, to angle northeast to the north shore of the mouth of the Maumee River. Much of Ohio features glaciated till plains, with an exceptionally flat area in the northwest being known as the Great Black Swamp; this glaciated region in the northwest and central state is bordered to the east and southeast first by a belt known as the glaciated Allegheny Plateau, by another belt known as the unglaciated Allegheny Plateau. Most of Ohio is of low relief, but the unglaciated Allegheny Plateau features rugged hills and forests; the rugged southeastern quadrant of Ohio, stretching in an outward bow-like arc along the Ohio River from the West Virginia Panhandle to the outskirts of Cincinnati, forms a distinct socio-economic unit. Geologically similar to parts of West Virginia and southwestern Pennsylvania, this area's coal mining legacy, dependence on small pockets of old manufacturing establishments, distinctive regional dialect set this section off from the rest of the state.
In 1965 the United States Congress passed the Appalachian Regional Development Act, an attempt to "address the persistent poverty and growing economic despair of the Appalachian Region." This act defines 29 Ohio counties as part of Appalachia. While 1/3 of Ohio's land mass is part of the federally defined Appalachian region, only 12.8% of Ohioans live there Significant rivers within the state include the Cuyahoga River, Great Miami River, Maumee River, Muskingum River, Scioto River. The rivers in the northern part of the state drain into the northern Atlantic Ocean via Lake Erie and the St. Lawrence River, the rivers in the southern part of the state drain into the Gulf of Mexico via the Ohio River and the Mississippi; the worst weather disaster in Ohio history occurred along the Great Miami River in 1913. Known as the Great Dayton Flood, the entire Miami River watershed flooded, including the downtown business district of Dayton; as a result, the Miami Conservancy District was created as the first major flood plain engineering project in Ohio and the United States.
Grand Lake St. Marys in the west-central part of the state was constructed as a supply of water for ca
Mayfield Heights, Ohio
Mayfield Heights is a city in Cuyahoga County, United States, is an east-side suburb of Cleveland. The population was 18,827 at the 2010 census. Mayfield Heights was built up as a streetcar suburb, it was incorporated as a village in 1925 and as a city in 1951. The city derives its name from Mayfield Township, now defunct. One location in the city, the W. A. Thorp House, was listed on the National Register of Historic Places in 1978. Mayfield Heights is located at 41°31′03″N 81°27′21″W. According to the United States Census Bureau, the city has a total area of 4.18 square miles, of which 4.17 square miles is land and 0.01 square miles is water. 23.9% were of Italian, 14.5% German, 11.9% Irish, 7.4% Polish, 6.8% Russian, 6.4% English ancestries. 81.0% spoke English, 7.11% Russian, 4.10% Italian, 1.03% Arabic as their first language. As of the census of 2010, there were 19,155 people, 9,662 households, 4,884 families residing in the city; the population density was 4,593.5 inhabitants per square mile.
There were 10,538 housing units at an average density of 2,527.1 per square mile. The racial makeup of the city was 80.4% White, 10.3% African American, 0.1% Native American, 7.0% Asian, 0.5% from other races, 1.7% from two or more races. Hispanic or Latino people of any race were 2.0% of the population. There were 9,662 households of which 21.2% had children under the age of 18 living with them, 36.0% were married couples living together, 11.2% had a female householder with no husband present, 3.3% had a male householder with no wife present, 49.5% were non-families. 44.2% of all households were made up of individuals and 20.5% had someone living alone, 65 years of age or older. The average household size was 1.97 and the average family size was 2.75. The median age in the city was 42.9 years. 17.6% of residents were under the age of 18. The gender makeup of the city was 45.3% male and 54.7% female. Of the city's population over the age of 25, 38.3% hold a bachelor's degree or higher. As of the census of 2000, there were 19,386 people, 9,848 households, 5,042 families residing in the city.
The population density was 4,596.1 people per square mile. There were 10,461 housing units at an average density of 2,480.1 per square mile. The racial makeup of the city was 91.85% White, 2.98% African American, 0.03% Native American, 4.03% Asian, 0.01% Pacific Islander, 0.18% from other races, 0.93% from two or more races. Hispanic or Latino people of any race were 1.04% of the population. There were 9,848 households out of which 17.9% had children under the age of 18 living with them, 40.1% were married couples living together, 8.2% had a female householder with no husband present, 48.8% were non-families. 44.5% of all households were made up of individuals and 22.5% had someone living alone, 65 years of age or older. The average household size was 1.95 and the average family size was 2.75. In the city the population was spread out with 16.1% under the age of 18, 6.6% from 18 to 24, 28.9% from 25 to 44, 20.8% from 45 to 64, 27.6% who were 65 years of age or older. The median age was 44 years.
For every 100 females, there were 82.2 males. For every 100 females age 18 and over, there were 78.9 males. The median income for a household in the city was $37,236, the median income for a family was $51,132. Males had a median income of $37,358 versus $29,118 for females; the per capita income for the city was $24,392. About 4.6% of families and 6.3% of the population were below the poverty line, including 6.3% of those under age 18 and 9.1% of those age 65 or over. Mayfield Heights is a part of the Mayfield City School District, along with Highland Heights, Mayfield Village, Gates Mills. Matt Prater, football placekicker for the Detroit Lions of the NFL. City website
Manufacturing is the production of products for use or sale using labour and machines, tools and biological processing, or formulation. The term may refer to a range of human activity, from handicraft to high tech, but is most applied to industrial design, in which raw materials are transformed into finished goods on a large scale; such finished goods may be sold to other manufacturers for the production of other, more complex products, such as aircraft, household appliances, sports equipment or automobiles, or sold to wholesalers, who in turn sell them to retailers, who sell them to end users and consumers. Manufacturing engineering or manufacturing process are the steps through which raw materials are transformed into a final product; the manufacturing process begins with the product design, materials specification from which the product is made. These materials are modified through manufacturing processes to become the required part. Modern manufacturing includes all intermediate processes required in the production and integration of a product's components.
Some industries, such as semiconductor and steel manufacturers use the term fabrication instead. The manufacturing sector is connected with engineering and industrial design. Examples of major manufacturers in North America include General Motors Corporation, General Electric, Procter & Gamble, General Dynamics, Boeing and Precision Castparts. Examples in Europe include Volkswagen Siemens, FCA and Michelin. Examples in Asia include Toyota, Panasonic, LG, Samsung and Tata Motors. In its earliest form, manufacturing was carried out by a single skilled artisan with assistants. Training was by apprenticeship. In much of the pre-industrial world, the guild system protected the privileges and trade secrets of urban artisans. Before the Industrial Revolution, most manufacturing occurred in rural areas, where household-based manufacturing served as a supplemental subsistence strategy to agriculture. Entrepreneurs organized a number of manufacturing households into a single enterprise through the putting-out system.
Toll manufacturing is an arrangement whereby a first firm with specialized equipment processes raw materials or semi-finished goods for a second firm. Manufacturing Engineering Agile manufacturing American system of manufacturing British factory system of manufacturing Craft or guild system Fabrication Flexible manufacturing Just-in-time manufacturing Lean manufacturing Mass customization – 3D printing, design-your-own web sites for sneakers, fast fashion Mass production Ownership Packaging and labeling Prefabrication Putting-out system Rapid manufacturing Reconfigurable manufacturing system Soviet collectivism in manufacturing History of numerical control Emerging technologies have provided some new growth in advanced manufacturing employment opportunities in the Manufacturing Belt in the United States. Manufacturing provides important material support for national infrastructure and for national defense. On the other hand, most manufacturing may involve significant environmental costs; the clean-up costs of hazardous waste, for example, may outweigh the benefits of a product that creates it.
Hazardous materials may expose workers to health risks. These costs are now well known and there is effort to address them by improving efficiency, reducing waste, using industrial symbiosis, eliminating harmful chemicals; the negative costs of manufacturing can be addressed legally. Developed countries regulate manufacturing activity with environmental laws. Across the globe, manufacturers can be subject to regulations and pollution taxes to offset the environmental costs of manufacturing activities. Labor unions and craft guilds have played a historic role in the negotiation of worker rights and wages. Environment laws and labor protections that are available in developed nations may not be available in the third world. Tort law and product liability impose additional costs on manufacturing; these are significant dynamics in the ongoing process, occurring over the last few decades, of manufacture-based industries relocating operations to "developing-world" economies where the costs of production are lower than in "developed-world" economies.
Manufacturing has unique health and safety challenges and has been recognized by the National Institute for Occupational Safety and Health as a priority industry sector in the National Occupational Research Agenda to identify and provide intervention strategies regarding occupational health and safety issues. Surveys and analyses of trends and issues in manufacturing and investment around the world focus on such things as: The nature and sources of the considerable variations that occur cross-nationally in levels of manufacturing and wider industrial-economic growth. In addition to general overviews, researchers have examined the features and factors affecting particular key aspects of manufacturing development, they have compared production and investment in a range of Western and non-Western countries and presented case studies of growth and performance in important individual industries and market-economic sectors. On June 26, 2009, Jeff Immelt, the CEO of General Electric, called for the United States to increase its manufacturing base employment to 20% of the workforce, commenting that the U.
S. has outsourced too much in some areas and can no longer rely on the financial sector and consumer spending to drive demand. Further, while U. S. manufacturing performs well compared to the rest of the U. S. economy, research shows that it performs poorly compared to manufacturing in other high-wage countries. A total of 3.2 million – one in six U. S. manuf
New York Stock Exchange
The New York Stock Exchange is an American stock exchange located at 11 Wall Street, Lower Manhattan, New York City, New York. It is by far the world's largest stock exchange by market capitalization of its listed companies at US$30.1 trillion as of February 2018. The average daily trading value was US$169 billion in 2013; the NYSE trading floor is located at 11 Wall Street and is composed of 21 rooms used for the facilitation of trading. A fifth trading room, located at 30 Broad Street, was closed in February 2007; the main building and the 11 Wall Street building were designated National Historic Landmarks in 1978. The NYSE is owned by Intercontinental Exchange, an American holding company that it lists, it was part of NYSE Euronext, formed by the NYSE's 2007 merger with Euronext. The NYSE has been the subject of several lawsuits regarding fraud or breach of duty and in 2004 was sued by its former CEO for breach of contract and defamation; the earliest recorded organization of securities trading in New York among brokers directly dealing with each other can be traced to the Buttonwood Agreement.
Securities exchange had been intermediated by the auctioneers who conducted more mundane auctions of commodities such as wheat and tobacco. On May 17, 1792 twenty four brokers signed the Buttonwood Agreement which set a floor commission rate charged to clients and bound the signers to give preference to the other signers in securities sales; the earliest securities traded were governmental securities such as War Bonds from the Revolutionary War and First Bank of the United States stock, although Bank of New York stock was a non-governmental security traded in the early days. The Bank of North America along with the First Bank of the United States and the Bank of New York were the first shares traded on the New York Stock Exchange. In 1817 the stockbrokers of New York operating under the Buttonwood Agreement instituted new reforms and reorganized. After sending a delegation to Philadelphia to observe the organization of their board of brokers, restrictions on manipulative trading were adopted as well as formal organs of governance.
After re-forming as the New York Stock and Exchange Board the broker organization began renting out space for securities trading, taking place at the Tontine Coffee House. Several locations were used between 1865, when the present location was adopted; the invention of the electrical telegraph consolidated markets, New York's market rose to dominance over Philadelphia after weathering some market panics better than other alternatives. The Open Board of Stock Brokers was established in 1864 as a competitor to the NYSE. With 354 members, the Open Board of Stock Brokers rivaled the NYSE in membership "because it used a more modern, continuous trading system superior to the NYSE’s twice-daily call sessions." The Open Board of Stock Brokers merged with the NYSE in 1869. Robert Wright of Bloomberg writes that the merger increased the NYSE's members as well as trading volume, as "several dozen regional exchanges were competing with the NYSE for customers. Buyers and dealers all wanted to complete transactions as and cheaply as technologically possible and that meant finding the markets with the most trading, or the greatest liquidity in today’s parlance.
Minimizing competition was essential to keep a large number of orders flowing, the merger helped the NYSE to maintain its reputation for providing superior liquidity." The Civil War stimulated speculative securities trading in New York. By 1869 membership had to be capped, has been sporadically increased since; the latter half of the nineteenth century saw rapid growth in securities trading. Securities trade in the latter nineteenth and early twentieth centuries was prone to panics and crashes. Government regulation of securities trading was seen as necessary, with arguably the most dramatic changes occurring in the 1930s after a major stock market crash precipitated the Great Depression; the Stock Exchange Luncheon Club was situated on the seventh floor from 1898 until its closure in 2006. The main building, located at 18 Broad Street, between the corners of Wall Street and Exchange Place, was designated a National Historic Landmark in 1978, as was the 11 Wall Street building; the NYSE announced its plans to merge with Archipelago on April 21, 2005, in a deal intended to reorganize the NYSE as a publicly traded company.
NYSE's governing board voted to merge with rival Archipelago on December 6, 2005, became a for-profit, public company. It began trading under the name NYSE Group on March 8, 2006. A little over one year on April 4, 2007, the NYSE Group completed its merger with Euronext, the European combined stock market, thus forming NYSE Euronext, the first transatlantic stock exchange. Wall Street is the leading US money center for international financial activities and the foremost US location for the conduct of wholesale financial services. "It comprises a matrix of wholesale financial sectors, financial markets, financial institutions, financial industry firms". The principal sectors are securities industry, commercial banking, asset management, insurance. Prior to the acquisition of NYSE Euronext by the ICE in 2013, Marsh Carter was the Chairman of the NYSE and the CEO was Duncan Niederauer. Presently, the chairman is Jeffrey Sprecher. In 2016, NYSE owner Intercontinental Exchange Inc. earned $419 million in listings-related revenues.
The exchange was closed shortly after the beginning of World War I, but it re-opened on November 28 of that year in order to help the war effort by trading bonds, reopened for stock tradin
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