Aarushhh/wikipedia-simple-splitted huggingface dataset:
In 1776, Thomas Paine wrote a pamphlet called Common Sense. It argued that the colonies should be free of English rule. This was based on the English ideas of natural rights and social contract put forth by John Locke and others. On July 4, 1776, people from the 13 colonies agreed to the United States Declaration of Independence. This said that they were free and independent states, and were not part of England any more. The colonists were already fighting Britain in the Revolutionary War at this time. The Revolutionary War started in 1775 at Lexington and Concord. Though American soldiers under George Washington lost many battles to the British, they won a major victory at Saratoga in 1777. This led to France and Spain joining the war on the side of the Americans. In 1781, an American victory at Yorktown helped by the French led Britain to decide to stop fighting and give up the colonies. America had won the war and its independence.

The Federal Period (1781–1815)
In 1781, the colonies formed a confederation of states under the Articles of Confederation, but it lasted only six years. It gave almost all the power to the states and very little to the central government. The confederation had no president. It could not remove Native Americans or the British from the frontier, nor could it stop mob uprisings such as Shays' Rebellion. After Shays' Rebellion, many people thought the Articles of Confederation were not working.

In 1787, a constitution was written. Many of the people who helped write the Constitution, such as Washington, James Madison, Alexander Hamilton and Gouverneur Morris, were among the major thinkers in America at the time. Some of these men would later hold important offices in the new government. The constitution created a stronger national government that had three branches: executive (the President and his staff), legislative (Congress, the House of Representatives and the Senate), and judicial (the federal courts).
Some states agreed to the Constitution very quickly. In other states, many people did not like the Constitution because it gave more power to the central government and had no bill of rights. To try and get the Constitution passed, Madison, Hamilton and Jay wrote a series of newspaper articles called the Federalist Papers. Very soon after, the Bill of Rights was added. This was a set of 10 amendments (changes), that limited the government's power and guaranteed rights to the citizens. Like the Declaration of Independence, the Constitution is a social contract between the people and the government. The main idea of the Constitution is that the government is a republic (a representative democracy) elected by the people, who all have the same rights. However, this was not true at first, when only white males who owned property could vote. Because of state laws as well as the 14th, 15th, 19th, 24th and 26th Amendments, almost all American citizens who are at least 18 years old can vote today.
In 1789, Washington was elected the first President. He defined how a person should act as President and retired after two terms. During Washington's term, there was a Whiskey Rebellion, where country farmers tried to stop the government from collecting taxes on whiskey. In 1795, Congress passed the Jay Treaty, which allowed for increased trade with Britain in exchange for the British giving up their forts on the Great Lakes. However, Great Britain was still doing things that hurt the U.S., such as impressment (making American sailors join the British Royal Navy).

John Adams defeated Thomas Jefferson in the election of 1796 to become the second President of the United States. This was the first American election that was between two political parties. As president, Adams made the army and navy larger. He also got the Alien and Sedition Acts passed, which were much disliked.
Expansion Industrialization And Slavery (1815–1861) 
One of the problems of this period was slavery. By 1861, over three million African-Americans were enslaved in the South. This means that they worked for other people, but had no freedom and received no money for their work. Most worked picking cotton on large plantations. Cotton became the main crop in the South after Eli Whitney invented the cotton gin in 1793. There were a few slave rebellions against slavery, including one led by Nat Turner. All of these rebellions failed. The South wanted to keep slavery, but by the time of the Civil War, many people in the North wanted to end it. Another argument between the North and South was about the role of government. The South wanted stronger state governments, but the North wanted a stronger central government.
People started to move west of the Mississippi River and the Rocky Mountains at this time. The first people who moved west were people who caught and sold animal skins such as John Colter and Jim Bridger. By the 1840s, many people were moving to Oregon by wagon, and even more people went west after the California Gold Rush of 1849. Many new states were added to the first thirteen, mostly in the Midwest and South before the Civil War and in the West after the Civil War. During this period, Native Americans lost much of their land. They had lost military battles to the Americans at Tippecanoe and in the Seminole War. In the 1830s, Indians were being pushed out of the Midwest and South by events such as the Trail of Tears and the Black Hawk War. By the 1840s, most Native Americans had been moved west of the Mississippi River.

The MexicanAmerican War ( 1846—1848 )
In 1845, Texas, which was a nation after it left Mexico, joined the United States. Mexico did not like this, and the Americans wanted the land Mexico had on the West Coast (“Manifest Destiny”). This led to the U.S. and Mexico fighting a war called the Mexican-American War. During the war, the U.S captured the cities of San Francisco, Los Angeles, Monterrey, Veracruz and Mexico City. As a result of the war, the U.S. gained land in California and much of the American Southwest. Many people in the North did not like this war, because they thought it was just good for Southern slave states.

Civil War
Civil War 

In the 1840s and 1850s, people in the Northern states and people in the Southern states did not agree whether slavery was right or wrong in the territories—parts of the United States that were not yet states. People in the government tried to make deals to stop a war. Some deals were the Compromise of 1850 and the Kansas-Nebraska Act, but they did not really work to keep the Union together. People in the South were angry at books like Uncle Tom’s Cabin that said that slavery was wrong. People in the North did not like a Supreme Court decision called Dred Scott that kept Scott a slave. People from the South and people from the North started killing each other in Kansas over slavery. This was called "Bleeding Kansas". One of the people from Bleeding Kansas, John Brown, took over a town in Virginia in 1859 to make a point about slavery being wrong and to try to get slaves to fight their owners.
Early in the war, Confederate generals such as Robert E. Lee and Stonewall Jackson won battles over Union generals such as George B. McClellan and Ambrose Burnside. In 1862 and 1863, the Union Army tried to take the Confederate capital of Richmond, Virginia several times, but failed each time. Lee's army invaded the North twice, but was turned back at Antietam and Gettysburg. In the middle of war, Lincoln made the Emancipation Proclamation, which freed all slaves in the Confederacy, and started letting black men fight in the Union Army. The war started going the Union’s way after the battles of Gettysburg and Vicksburg in 1863. Gettysburg stopped Lee from invading the North, and Vicksburg gave the Union control over the Mississippi River. In 1864, a Union Army under William T. Sherman marched through Georgia and destroyed much of it. By 1865, Union General Ulysses S. Grant had taken Richmond and forced Lee to give up the fight at Appomattox.

Reconstruction and the Gilded Age
During this time, many people moved to the United States from other countries, such as Ireland, Italy, Germany, Eastern Europe, and China. Many of them worked in large factories and lived in big cities, such as New York City, Chicago, and Boston, often in small, poor, close-together apartments called "tenements" or "slums". They often were used by "political machines", who gave them jobs and money in exchange for votes.

Major politicians were chosen by political machines and were corrupt. The government could do little and leaders of big businesses often had more power than the government. At this time, there were several very big businesses called trusts. People who ran trusts made millions of dollars while paying their workers low wages. Some of these people were John D. Rockefeller, Andrew Carnegie, and J.P. Morgan.
Many Americans thought the railroads charged farmers so much money that it made them poor. Workers led several strikes against the railroad that were put down by the army. Also, farmers started groups to fight the railroad, such as the Grange. These groups became the Populist Movement, which almost won the presidency under William Jennings Bryan. The Populists wanted reforms such as an income tax and direct election of Senators. The Populist Party died out after 1896. Many of the things the Populists wanted would happen during the Progressive Era.

Progressive era and imperialism 

In the United States, progressivism is the belief that the government should have a larger role in the everyday life of Americans to provide good living standards for people, especially workers. Imperialism was the belief that the U.S. should build a stronger navy and conquer land.
In 1912, Woodrow Wilson became President. He was a Progressive, but not quite the same as Roosevelt. He fought the "triple wall of privilege", which was big business, taxes, and fees on goods coming into the United States. During this time, the Sixteenth and Seventeenth Amendments to the U.S. Constitution were passed. They allowed for a federal income tax and direct election of U.S. Senators.

World War I
World War I 

The United States did not want to enter World War I but wanted to sell weapons to both sides. In 1915 a German submarine sank a ship carrying Americans called the Lusitania. This angered Americans, and Germany stopped attacking passenger ships. In January 1917 Germany started attacking them again, and sent the Zimmerman Telegram to Mexico about invading the U.S. The United States joined the war against Germany, and it ended a year later. Wilson worked to create an international organization called the League of Nations. The main goal of the League was preventing war. However, the United States did not join because isolationists rejected the peace treaty. At the end of World War I, a flu pandemic killed millions of people in the U.S. and Europe. After the war, the United States was one of the richest and most powerful nations in the world.

Boom and bust (1919–1939)

The "Roaring Twenties"
Racism was strong in the 1920s. The Ku Klux Klan was powerful once again, and attacked black people, Catholics, Jews and immigrants. People blamed the war and problems in business on immigrants and labor leaders, whom they said were Bolsheviks (Russian communists). Many people also thought that the United States had lost touch with religion. They handled that by changing religion, and some of them by attacking science.

After World War I, the United States had an isolationist foreign policy. That meant it did not want to enter into another global war. It passed laws and treaties that supposedly would end war forever, and refused to sell weapons to its former allies.
In 1921, Warren G. Harding became President. He believed that the best way to make the economy good was for the government to be friendly to big business by cutting taxes and regulating less. While the economy was doing very well under these policies, America had the largest difference between how much money the rich had and how much money the poor had. Harding's presidency had several problems. The biggest one was Teapot Dome over oil drilling in the Navy Oil Reserve. Harding died in 1923, and Calvin Coolidge became President. Coolidge believed that the government should keep out of business, just like Harding, and continued many of Harding's policies. Coolidge chose not to seek the presidency in 1928 and Herbert Hoover became president.

The Great Depression
In 1929, a Great Depression hit the United States. The stock market crashed (lost much of its value). Many banks ran out of money and closed. By 1932, over a quarter of the nation had no jobs, and much of the nation was poor or unemployed. Many people were driven off farms, not only because of the Depression, but also because of a storm known as the "Dust Bowl" and because farmers had not been doing well during the 1920s.

President Hoover tried to do something about the Depression, but it did not work. In 1932, he was defeated and Franklin D. Roosevelt became President. He created the New Deal. It was a series of government programs which would give relief (to the people who were hurt by the bad economy), recovery (to make the economy better), and reform (to make sure a depression never happens again).
The New Deal is often called the period that "saved capitalism", and stopped America from becoming a Communist or Fascist state. Although the New Deal improved the economy, it did not end the Great Depression. The Great Depression was ended by World War II.

World War II 

As World War II was beginning, the United States said they would not get involved in it. Most Americans thought the United States should remain neutral, and some people thought the United States should enter the war on the side of the Germans. Eventually, the U.S. did try to help the Allied Powers (Soviet Union, Britain, and France) with the Lend Lease Act. It gave the Allies a lot of money and guns in trade for use of air bases throughout the world.
The war meant different things for women and minorities. During the war, many women worked in weapons factories. They were symbolized by a character called "Rosie the Riveter". Many African-Americans served in the army, but often in segregated units with white officers. Japanese-Americans on the West Coast were forced to live in internment camps, though a few also served in the Army.

Postwar era (1945–1991)

Cold War 

After World War II, the Soviet Union and the United States were the two most powerful countries left in the world. The Cold War was a period of tension between the two countries over ways of life. The two countries tried to get other countries on their side. The Soviet Union tried to get countries to become Communist and the United States tried to stop them from being Communist. American and Soviet soldiers never fought in battles, but they fought indirectly in the Korean War (1950s) and the Vietnam War (1950s–1970s).
Besides the arms race, another part of the Cold War was the "Space Race". This started when the Soviets launched a satellite into space called Sputnik in 1957. Americans became worried that the United States was falling behind the Soviet Union, and made their schools focus more on mathematics and science. Within a few years, both the United States and the Soviet Union had sent satellites, animals and people into orbit. In 1969 the Apollo 11 mission put Neil Armstrong and Buzz Aldrin on the Moon.
United States foreign policy changed in the 1970s when the United States left Vietnam and Richard Nixon left office due to a political scandal called Watergate. In the 1970s and 1980s, the United States had a policy of "detente" with the Soviet Union. This meant that the two countries signed treaties to stop use of weapons. Under Nixon and Reagan, the United States sent troops and money to many Latin American governments to stop them from being Communist. This led to violence in Latin America. Around this time, the economy suffered because the United States was not making as many things as it used to, and because some countries in the Middle East were not giving the U.S. as much oil as it wanted (this was called an "oil embargo"). The Middle East became very important in American foreign policy after several Americans were kidnapped in Iran in 1979. In the 1980s, people in the U.S. government sold weapons to people in Iran and gave the money to "contra" soldiers in Nicaragua
. This was called the "Iran-Contra affair". In the 1970s and 1980s, the U.S. normalized relations with China. The Cold War came to an end as Communist governments in the Soviet Union and other countries fell apart.
Domestic and social issues 

The United States once again had prosperity. Millions of white people moved out of the cities and into suburbs, and into Southern and Western states known as the "Sunbelt". They bought new cars and television sets. The birth rate in the 1940s and 1950s rose, in what was called the "Baby Boom" The "Space Age" inspired "Googie" style art and architecture. Many more people became part of the middle class, but there were still many people who were poor.
Poverty was most common among African-Americans. Most lived in poor neighborhoods in Northern cities, or in the South where they faced racism and "Jim Crow" segregation. These conditions led to the Civil Rights Movement of the 1950s, led by Martin Luther King Jr. and others. In 1954, the Supreme Court found school segregation illegal in Brown v. Board of Education, though it would be several years before school segregation was ended. In 1955, King led a bus boycott in Montgomery, Alabama. In the late 1950s and 1960s, King got help from Presidents John F. Kennedy, who was shot, and Lyndon B. Johnson. In 1963, he led a march on Washington calling for civil rights. Soon after, Congress passed laws that made most segregation illegal. Johnson also passed a program called the Great Society that helped poor people and minorities.
Gays and lesbians, who had often been persecuted, also started to ask for rights, beginning with the Stonewall riots in 1969. Chicanos, Native Americans, old people, consumers, and people with disabilities also fought for rights, as did women. Though women had had jobs during World War II, most of them went back to the home after the war. Women did not like that they often held jobs that paid less than men or that fewer opportunities were open to them. People like Betty Freidan and Gloria Steinem founded groups such as the National Organization for Women to try and solve these problems. NOW and other groups wanted an Equal Rights Amendment that would guarantee them equality in all areas. In the 1970s and 1980s, many more jobs and opportunities were opened to women. There were some women like Phyllis Schlafly who opposed Freidan and Steinem and were known as "anti-feminists"
. It was partly because of the anti-feminists that the Equal Rights Amendment was defeated, but also because women had already gained equality in many areas and they did not want to be drafted into the army.
In the 1960s, the counterculture was created. Some of the followers of the counterculture were called hippies. They had long hair, and lived communally, smoking marijuana and practicing free love. The counterculture, along with college students, were the groups most against the Vietnam War. They also were the groups that listened to new music known as rock and roll.

In 1973, the Supreme Court issued a decision called Roe v. Wade, which made many abortions legal. The many changes led to a reaction by Jerry Falwell and other conservatives who called themselves the "Religious Right" and the "Moral Majority".

Reagan Era
Reagan Era 

Ronald Reagan was elected President in 1980. He defeated incumbent Jimmy Carter by winning 44 out of the 50 American states. During the Reagan Era, the country was facing through inflation, a bad economy, and the American foreign policy were not as good. When Ronald Reagan became president, he signed the Economic Recovery Tax Act of 1981 which lowered taxes for corporations, supposedly so they could reinvest the surplus profits back into business. During Reagan's presidency, he expanded the American military creating more jobs, but also raising the deficit due to overspending. During his first term, the economy went from a 4.5% to 7.2%.
In 1984, Reagan won in a major landslide by winning 49 out of the 50 American states. During his second term, Reagan focused on ending the Cold War. He held many meetings between Margaret Thatcher, Pope John Paul II, and Soviet leader Mikhail Gorbachev. They first met at the Geneva Summit in 1985. Later they both discovered their passion of ending the war. Reagan met four times with Soviet leader Mikhail Gorbachev, who ascended to power in 1985, and their summit conferences led to the signing of the Intermediate-Range Nuclear Forces Treaty.

Also during his second term, Reagan's Invasion of Grenada and bombing of Libya were popular in the US, though his backing of the Contras rebels was mired in the controversy over the Iran–Contra affair that revealed Reagan's poor management style.

Since leaving office in 1989, Reagan became one of the most popular Presidents of the United States.

Post-Cold War and beyond (1991–present)

Post-Cold War era
Post-Cold War era

In the late 1980s and early 1990s, Republican President Ronald Reagan brought the Cold War to an end. This was due to the Russian leader Mikhail Gorbachev starting a policy called perestroika, the fall of the Berlin Wall, and the Soviet Union breaking into different countries. Around this time, the United States cut down on its production of cheap goods, and had many people working in service jobs. Part of these service jobs were in computers and the internet, which came into wide use in the 1990s. By this time, the United States had a very large trade deficit, meaning it received more goods from other countries, such as China, than it sent to other countries.

The Middle East became the main focus of U.S. foreign policy. In 1991, the United States fought a war with Iraq called the First Gulf War or Operation Desert Storm. This was to stop Iraqi leader Saddam Hussein from occupying Kuwait, a small oil-producing country.
In 1992, Bill Clinton became President. Under Clinton, the United States sent soldiers into Bosnia as part of a United Nations mission. The United States also agreed to a trade pact called the North American Free Trade Agreement (and repealed Glass–Steagall Legislation). Clinton was impeached for lying in court about his relationship with Monica Lewinsky, but the Senate voted against removing him as President.

21st century

Bush presidency
In 2000, George W. Bush was elected President. Terrorists attacked the World Trade Center on September 11, 2001. Thousands of people died. Soon after the attacks, the U.S. and NATO went to Afghanistan to find Osama bin Laden and others who they believed planned the September 11 attacks. In 2003, the United States invaded Iraq. The wars in Iraq and Afghanistan have lasted many years. By 2011, American soldiers started leaving Iraq, and combat there started to slow down.
In 2005, the southern United States was hit by Hurricane Katrina. Much of the city of New Orleans was destroyed. In 2006, the Democrats won back Congress because Americans did not like the way Bush dealt with War in Iraq or Katrina.

Obama presidency
Barack Obama was elected President in 2008. The United States had entered the worst recession since the Great Depression a while before. Barack Obama was the first African-American President of the United States. During his first years in office, Obama and Congress passed reforms on health care and banking, skyrocketing the cost of health insurance. They also passed a large stimulus bill to try to help the economy during the recession, but it only ultimately extended it's duration. During the recession, the government used large amounts of money to keep the banking and auto industries from falling apart. There was also a large oil spill in the Gulf of Mexico. In 2010, Congress passed the Patient Protecton and Affordable Care Act, a sweeping overhaul of the health care system. Dubbed "Obamacare", it was faced with fierce criticism from conservative media, as it exponentially increased the cost of health care. However, it was praised by Democrats who said it helped give more people access to healthcare
. It continues to be a big deal to this day.
A "Tea Party movement" started during Obama's presidency. This group opposes Obama's health care plan and other policies they see as "big government." Due to the recession, the Tea Party and a dislike of what Obama did, Republicans won a large number of House and Senate seats in the 2010 election. In 2011, Tea Party members of Congress almost shut down the government and sent the U.S. into default (not being able to pay people the government owes money). A few months later, many young people protested against organized and concentrated wealth during the Occupy movement. In 2012, Obama was reelected to a second term. Following reelection, Obama faced major obstruction from Congressional Republicans. This polarization in the political atmosphere and the media, lead to events such as the 2013 Federal Government Shutdown and the stalling of Obama's Supreme Court pick, Judge Merrick Garland to replace Justice Antonio Scalia
. In 2014, Republicans took control of both houses of Congress, further adding to the gridlock. In foreign policy, President Obama helped craft the Paris Climate Agreement, a major global commitment to fighting "climate change". He also forged the Iran Nuclear Agreement, which was widely seen as an enormous failure. He also opened relations with Cuba for the first time in fifty years.
Trump presidency

The 2016 presidential election attracted much attention. Main popular candidates of the election were Republicans Donald Trump and Senator Ted Cruz and Democrats Hillary Clinton and Senator Bernie Sanders. Trump and Clinton won their respective primaries. On November 9, 2016, Trump defeated Clinton. Trump was inaugurated on January 20, 2017. Afterwards, there were many protests against Trump across the country.

On January 27, President Trump signed an executive order that stopped refugees from entering the country for 120 days and denied entry to citizens of Iraq, Iran, Libya, Somalia, Sudan, Syria, and Yemen for 90 days, citing security concerns about terrorism. The next day, thousands of protesters gathered at airports and other locations throughout the United States to protest the signing of the order and detainment of the foreign nationals. Later, the administration seemed to reverse a portion of part of the order, effectively exempting visitors with a green card.
On May 3, 2017, Puerto Rico filed for bankruptcy after a massive debt and weak economy. It is the largest bankruptcy case in American history.

On September 24, 2019, Speaker of the House Nancy Pelosi announced that the House of Representatives would begin an impeachment inquiry into Trump. On October 31, 2019, the House voted 232–196 to created procedures for public hearings. On December 16, the House Judiciary Committee released a report specifying criminal bribery and wire fraud charges as part of the abuse of power charge. The house voted to impeach Trump on December 18, 2019, making him the third president in American history to be impeached. No conclusive evidence of any criminal wrongdoing has ever been found or produced concerning President Trump.
During most of 2020, the United States was impacted by the COVID-19 pandemic that has impacted the world. The country became the highest infected and the most people dead from the infection, although there is much criticism concerning how the data was gathered.  The Trump administration received negative responses for their handling of the virus, despite the very successful Operation "warp speed" that produces the first vaccine to fight the virus.  Some people refuse to wear surgical masks to help stop the transmission of the virus. In some states, governors locked-down their states in an attempt to stop the spreading of the virus. 

Starting in May 2020, racial tensions in the country began to intensify through the police murder of George Floyd causing massive protests and rioting across the country. The Black Lives Matter movement began in grow popularity through mixed reception.
On November 7, 2020 former Vice President Joe Biden defeated President Trump in the country's highest voter turnout presidential election. Biden became the oldest person elected to the office and the first to be from the state of Delaware. Biden's running mate, U.S. Senator Kamala Harris was the first woman, African-American and Asian-American to be elected Vice President or any high-ranking elected office in the country.

On January 6, 2021 while members of the United States Congress met to certify Biden's electoral victory, alleged supporters of President Trump stormed into the United States Capitol attempting to overthrow the results of the 2020 election. Five people died. This led to the United States House of Representatives to impeach Trump for a second time, making him the only U.S. President to be impeached twice.

Biden's Presidency
Biden's Presidency

Following Biden's election, the date for US troops to withdraw from Afghanistan was moved back from April to August 31, 2021. In Afghanistan, the withdrawal coincided with the 2021 Taliban offensive, culminating in the fall of Kabul. Following a massive airlift of over 120,000 people, the US military mission formally ended on August 30, 2021.

On June 24, 2022, the Supreme Court, in a landmark ruling, determined that abortion is not a protected right under the Consititution. The ruling, Dobbs v. Jackson Women's Health Organization overturned Roe v. Wade and Planned Parenthood v. Casey and sparked protests outside of the Supreme Court building and across the country.

Ketanji Brown Jackson succeeded Justice Breyer upon his retirement from the court on June 30, 2022. She became the first black woman and the first former federal public defender to serve on the Supreme Court upon her swearing in.
The United States faces many political issues. One of these is what kind of government the United States should become. Liberals want a large government, while the Tea Party and other groups want a smaller government. One of these debates is over health care. Health care costs have risen. Conservatives and liberals also disagree on social issues such as abortion and gay marriage. Many more people have come to accept gays and gay marriage as an acceptable part of American society. There are also many trends and developments that the U.S. must deal with. One of these is immigration. Many people are coming to the U.S. from Latin America and Asia, especially Mexico. This is called the "browning of America". Baby Boomer Americans are getting older and a larger fraction of the people are retired. Other issues facing the United States are a growing concern about the environment
. This has led to the creation of many "green jobs," or jobs that create clean or renewable energy, often overlooking the negative effects that can occur from these initiatives, such as droughts caused by mining lithium for electric car batteries.
Related pages 
 Geography of the United States

References

Selected readings

Other websites

Book-length histories of the United States

General sites

U. S. National Archives

Other

Specialized topics

Other resources
In mathematics, the exponential function is a function that grows quicker and quicker. More precisely, it is the function , where e is Euler's constant, an irrational number that is approximately 2.71828.

Properties
Because exponential functions use exponentiation, they follow the same exponent rules. Thus,
. 

This follows the rule that .

The natural logarithm is the inverse operation of an exponential function, where:

The exponential function satisfies an interesting and important property in differential calculus:

This means that the slope of the exponential function is the exponential function itself, and as a result has a slope of 1 at . These properties are the reason it is an important function in mathematics.
Applications
The general exponential function, where the base is not necessarily , is among the most useful of mathematical functions. It is used to represent exponential growth, which has uses in virtually all scientific disciplines and is also prominent in finance. Another application of the exponential function is exponential decay, which occurs in radioactive decay and the absorption of light.

One example of an exponential function in real life would be interest in a bank. If a person deposits £100 into an account which gets 3% interest a month, then the balance each month (assuming the money is untouched) would be as follows:

Here, notice how the extra money from interest increases each month, in that the greater the original balance, the more interest the person will get.

Two mathematical examples of exponential functions (with base a) are shown below.

a=2
 

a=3

Relation to the mathematical constant e
Even though the base () can be any number bigger than zero, for example, 10 or 1/2, often it is a special number called e. The number e cannot be written exactly, but it is almost equal to 2.71828.

The number e is important to every exponential function. For example, a bank pays interest of 0.01 percent every day. One person takes his interest money and puts it in a box. After 10,000 days (about 30 years), he has 2 times as much money as he started with. Another person takes his interest money and puts it back into the bank. Because the bank now pays him interest on his interest, the amount of money is an exponential function. 

In fact, after 10,000 days, he does not have 2 times as much money as he started with, but he has 2.718145 times as much money as he started with. This number is very close to the number e. If the bank pays interest more often, so the amount paid each time is less, then the number will be closer to the number e.
A person can also look at the picture to see why the number e is important for exponential functions. The picture has three different curves. The curve with the black points is an exponential function with a base slightly smaller than e. The curve with the short black lines is an exponential function with a base slightly bigger than e. The blue curve is an exponential function with a base exactly equal to e. The red line is a tangent to the blue curve. It touches the blue curve at one point without crossing it. A person can see that the red curve crosses the x-axis, the line that goes from left to right at -1. This is true only for the blue curve. This is the reason that the exponential function with the base e is special.

Related pages 

 Logarithm

References 

Functions and mappings
A computer file is a means to store information that belongs together. Computer files can be opened (read and written) by computer programs. Usually they are stored on some kind of file system.

There are different kinds of computer files that hold different kinds of data (information):

 Text files
 Audio files (e.g. for songs, voice recordings)
 Video files (e.g. for movies)
 Images (pictures)
 Other binary data

The way the information is organized in a file is called the file format.

Computing
Data format in information technology can mean:
 Data type, constraint placed upon the interpretation of data in a type system
 Recording format, a format for encoding data for storage on a storage medium
 File format, a format for encoding data for storage in a computer file
 Content format, a format for converting data to information
 Audio format, a format for processing audio data
 Video format, a format for processing video data
A file is a tool used to shape materials, by wearing away some of it. Today, files are usually made of a steel bar that has a rough surface. By rubbing the surface against a material, some of the material is scraped away.  There are also nail files used to shape a person's fingernails. Files can also make a surface smooth so that there are no gaps, which is useful when two surfaces need to be attached to each other. A file is "blunt" if it is the same size on both ends, and "tapered" if one end is smaller than the other.

Cutting tools
Sheffield Wednesday F.C. is an English football club. They are based in Sheffield, South Yorkshire. They play their home matches at a stadium called Hillsborough Stadium. They originally played at a stadium called Olive Grove Stadium and were called The Wednesday.

The club plays in the English Football League Championship.

Fans of Sheffield Wednesday are referred to as Owls. The team's symbol is an owl.

Name 
 1867-1929 The Wednesday C.C./F.C.
 1929-present Sheffield Wednesday F.C.

League position

Former position

Other websites 
 Sheffield Wednesday website

References 

Football clubs in Sheffield
1867 establishments in England
De Wallen ("thin walls") are the biggest and most famous red-light district in Amsterdam. It is in the very old (14th century) part of the city around the Oude Kerk and Oudezijds Achterburgwal/Vorburgwal.

In December 2007, the mayor of Amsterdam and his government decided to buy many of brothelhouses within De Wallen. By doing this, the area used for prostitution and coffee shops gets smaller and smaller.

References

Amsterdam
Red light districts
Wolverhampton Wanderers are an English association football club.  They are based in Wolverhampton, West Midlands.  The club started in 1877 and play their home games at a stadium called Molineux Stadium.  They have never won the FA Cup.

In 2009 they won the Football League Championship.  This meant they were promoted into the Premier League for the following season.  Also promoted were runners-up Birmingham City F.C., and Burnley F.C. from the play-offs.

Name 
 1877-? St. Luke's F.C.
 ?-present Wolverhampton Wanderers F.C.

League position

Former position

References 

English football clubs
1877 establishments in England
Wolverhampton
Association Football Club Bournemouth, known in short name as A.F.C. Bournemouth, are an English football club.  They are based in Bournemouth and play their home games at a stadium called the Vitality Stadium.  They started in 1899 and have had Harry Redknapp as a manager and his son Jamie Redknapp as a player. They are currently in the Premier League.

Name 
1899–1923 Boscombe F.C.
1923–1971 Bournemouth & Boscombe Athletic F.C.
1971–present A.F.C. Bournemouth

Players

Current squad

Out on loan

League position

Former position

Other websites 
Official A.F.C. Bournemouth website

References

Premier League clubs
Bournemouth
1899 establishments in England
Jamie Redknapp (born 25 June 1973) is an English footballer. He was born in Barton on Sea, Hampshire. He played for Liverpool F.C., Tottenham Hotspur F.C., A.F.C. Bournemouth and Southampton F.C..  His father, Harry Redknapp, is the manager of Portsmouth F.C.

Redknapp married R&B singer Louise Nurding in 1998.

1973 births
Living people
English footballers
Sportspeople from Hampshire
Louise Redknapp
Premier League players
Bradford City A.F.C. is an English football club.  They are based in Bradford, West Yorkshire.  They began in 1903 and play their home games in a stadium called Valley Parade.

League position

Former position

References

Bradford
English football clubs
1903 establishments in the United Kingdom
Organisations based in West Yorkshire
Arenal Volcano National Park is a national park in the northwest region of Costa Rica. It is between the mountain pass of the Tilarán Mountain Range and the Plains of San Carlos. A part of the park belongs to San Ramón.

Attractions

Arenal Volcano 
The main characteristic of this national park is the Arenal Volcano. It is an almost perfect cone with a height of 1633 m. The volcano has regular eruptions which create one of the most extraordinary natural landscapes of Costa Rica.

Wildlife 
The park many different types of plants and animals. Some of the more interesting plants are Guayabo mountain, Ceiba, Cirri, Laurel, Higuerones, Pilon, Guarumo, Balsa, different species of palms, heliconias, orchids, ferns and bromeliads including Pitcaimia Funkiae.
The main species of animals are sloths, birds like lapas, parrots and quetzals, snakes like lora snake, velvet snake and the boa constrictor, 35 species of fish and 135 species of reptiles including turtles. There are also tapirs, deers, jaguars, sahínos, pizotes, Congo monkeys, and cappuccino monkeys. Most of the animals that live in the park are birds. This makes the park a very good place for bird watchers.

Scenery 
This national park has a great tourist attraction because of the beautiful scenery and  forests. It is also a very good place for extreme sports practice like canopy which hundreds of peoples both foreigners and locals like a lot. Many people like to watch the view created by the volcano when it is making small eruptions at night.

National parks in Costa Rica
Alajuela Province
"Faded" is a 2006 song by Kate DeAraugo, the winner of Australian Idol in 2005.

2006 songs
"Emergency" is a 2005 song by Paramore. It came off the album All We Know Is Falling.

The song is about Hayley Williams' parents, and she could remember standing between them yelling at them to shut up.

2005 songs
Paramore songs
Roger David Kornberg (born ) is an American biochemist and Nobel prize winner. Kornberg got the Nobel Prize in Chemistry in 2006 for studying eukaryote transcription (the copying of information from DNA to RNA). 

Kornberg is a professor of Structural Biology at Stanford University School of Medicine. His father, Arthur Kornberg, was also a professor at Stanford University, and got the Nobel Prize in Physiology or Medicine in 1959.

Early life 
Kornberg was born in St. Louis, Missouri to a Jewish family. He was the first of three children born to Arthur Kornberg and his wife, Sylvy. The parents worked together as biochemists. Roger Kornberg earned his bachelors degree from Harvard University in 1967 and his PhD from Stanford University in 1972. He then became a Fellow at the Laboratory of Molecular Biology at the University of Cambridge, England.
Important studies 
All heredity is controlled by genes. For the cells to make use of the information in the genes, a copy of part of the gene must be made. The copying is called transcription. Transcription makes an RNA copy of part of the DNA. The RNA is moved out of the cell nucleus, to ribosomes, where it does its work. This is called messenger RNA and it gives the amino acid sequence for protein production. This second process is called translation. It works in all eukaryotes, including all plants and animals.

Kornberg worked with Aaron Klug and Francis Crick at the MRC in the 1970s. He discovered the nucleosome, a very important protein structure in chromosomes. Nucleosomes form the basic repeating units of eukaryotic chromatin. This packs the large eukaryotic genomes into the nucleus and allows it to be controlled.
Kornberg made the discovery that signals to the RNA are made by a complex of proteins that they called mediator. The Nobel Prize committee said, "the great complexity of eukaryotic organisms is enabled by the fine interplay between tissue-specific substances, enhancers in the DNA and mediator. The discovery of mediator is therefore a true milestone in the understanding of the transcription process".

After long effort, Kornberg was able to use X-ray crystallography to take 3D pictures of RNA molecules, lipids and proteins. With these studies, Kornberg has created a picture of how DNA works. The Nobel Prize committee said, "the truly revolutionary aspect of the picture Kornberg has created is that it captures the process of transcription in full flow. What we see is an RNA-strand being constructed, and hence the exact positions of the DNA, polymerase and RNA during this process".
Awards 
Professor Kornberg has received these awards:
 1997: Harvey Prize from the Technion – Israel Institute of Technology
 2002: ASBMB-Merck Award
 2002: Pasarow Award in Cancer Research
 2002: Le Grand Prix Charles-Leopold Mayer
 2005: General Motors Cancer Research Foundation’s Alfred P. Sloan Jr. Prize
 2006: Nobel Prize in Chemistry
 2006: Louisa Gross Horwitz Prize from Columbia University

References

Other websites 
 Roger Kornberg Laboratory
 List of Kornberg's publications
 The Nobel Foundation home page
 Press release from The Royal Swedish Academy of Sciences 
 A brief biography of his life 
 Further biographical details 
 BBC News report of his Nobel Prize win
 The Official Site of Louisa Gross Horwitz Prize

1947 births
Living people
American chemists
American Nobel Prize winners
Harvard University alumni
Jewish American academics
Jewish American scientists
Jewish Nobel Prize winners
Scientists from St. Louis, Missouri
Stanford University faculty
Educators from St. Louis, Missouri
All We Know Is Falling is the first album of the band Paramore. It was recorded in just three weeks. In April 2006, the CD was released in the United Kingdom. In 2005, a Japanese version was released, with the bonus track "O, Star".

Track listing 
 "All We Know" - 3:13
 "Pressure" - 3:05
 "Emergency" - 4:00
 "Brighter" - 3:43
 "Here We Go Again" - 3:46
 "Never Let This Go" - 3:40
 "Whoa" - 3:21
 "Conspiracy" - 3:42
 "Franklin" - 3:18
 "My Heart" - 3:59

Japanese bonus tracks 

 "Oh, Star" - 3:50
 "Here We Go Again" (Acoustic)
 "Hallelujah" (Acoustic)

Music videos 

Paramore released three videos from this album. The first was for the single "All We Know", followed by "Pressure", and "Emergency".

Credits 
 Hayley Williams – vocals
 Josh Farro – lead guitar, backing vocals
 Zac Farro – drums, percussion
 Jeremy Davis – bass
 Jason Bynum – Rhythm guitar (He left the band in 2005)
 Taylor York – Rhythm guitar

Other websites 
 All We Know Is Falling at MusicBrainz
2005 albums
Paramore albums
Debut albums
Pop punk albums
Rock albums
A businessperson (also businessman or businesswoman) is someone who works at a job that focuses on making money. Very broadly it can mean anyone who works in industry or commerce. More narrowly, it is someone who works in the management (at high level, when the term is used even more narrowly) of a company. Sometimes the word means an entrepreneur or a merchant.

Many businessmen wear standard business clothes: a suit with collar, shirt, and necktie. However, this depends on the company, the local culture, and the country. In more informal places, neckties need not be worn.

Businesswomen clothes have gone through many changes. Dresses and suits are common today.

References 

Business occupations
Werl is a town in the district of Soest in North Rhine-Westphalia, Germany.

Geography

Divisions of the town 
Werl is made up of the following districts:
 Blumenthal (48 inhabitants)
 Budberg (596 inhabitants)
 Büderich (3107 inhabitants) 
 Hilbeck (1339 inhabitants)
 Holtum (1049 inhabitants)
 Mawicke (521 inhabitants)
 Niederbergstraße (210 inhabitants)
 Oberbergstraße (363 inhabitants)
 Sönnern (870 inhabitants)
 Westönnen (2665 inhabitants)
 Werl (22151 inhabitants)

People
Werl was the birthplace of Franz von Papen (1879–1969), German soldier, politician and diplomat.

References

Other websites

Towns in North Rhine-Westphalia
Soest (district)
In geometry, a tangent is a straight line that touches a curve at one point. At the place where they touch, the line and the curve both have the same slope (they are both "going in the same direction"). For this reason, a tangent line is a good approximation of the curve near that point. The curve and the tangent line are almost exactly the same near the intersection point. 

A straight line which touches a circle at a single point is perpendicular to the circle's radius and is considered tangent to the circle.

Uses 
Tangent lines are useful in calculus because they can magnify the slope of a curve at a single point. The slope of some curve at the point P is often called the instantaneous rate of change of the curve at P. The instantaneous rate of change at a specific point on the curve can be found by evaluating the derivative function for the curve at that point.

Related pages
Derivative (mathematics)
Calculus
Trigonometric function

Geometry
The History of North America deals with an area where humans came to live relatively recently, compared to Africa, Europe, and Asia.

Scientists have different theories as to the origins of the early human population of the continent.  The indigenous peoples of North America themselves have many creation stories, that tell that native Americans have been present on the land since its creation.

Pre-Columbian Era