The highest point in the United States of America is Mount McKinley (6,194 m).
The Barringer Crater (Meteor Crater) in Arizona, estimated to be 49,000 years old, is 1.2 km across and 100 m deep.
The Mississippi-Missouri is the longest river in the USA.
Lake Michigan, one of the Great Lakes, is the USA's largest lake.
Six hundred and forty thousand years ago, a massive volcanic eruption took place in present-day Yellowstone Park (Wyoming). The caldera is seventy kilometres long and thirty kilometres wide. Yellowstone became the world's first National Park in 1872.
Skeletons of prehistoric animals buried by volcanic ash in the State of Nebraska can be seen at the Ashfall State Historical Park.
Twenty thousand years ago nomadic people, thought to have traveled from Asia, hunted mammoths and antelope in New Mexico.
Recent studies point to a very early migration of people to America across the Atlantic. One theory is that the Solutrean Neolithic (Stone Age) people from southwest France may have made the journey.
Poverty Point, Louisiana, is an archaeological site dating back to 2200 BC. It contains a geometric earthwork complex, consisting of over eleven miles of raised terraces.
In the sixth century AD the Ancestral Pueblo built villages in the south-west of the country. An example of Ancestral Pueblo architecture can be seen in Mesa Verde National Park.
The pre-Columbian settlement of Cahokia (800-1400 AD), near St Louis, had a population of twenty thousand people.
About a thousand years ago Leif Ericson (born in Iceland) made voyages along the North American coast.
The voyages of Christopher Columbus to the New World took place between 1492 and 1504.
The explorer Amerigo Vespucci gave his name to America.
When the first settlers arrived in America millions of buffalo roamed the plains.
The Indian princess Pocahontas (1595-1617) was a friend to the colonists of Jamestown in Virginia at a time when they were finding life difficult. During a period when she was held captive, to exchange for English prisoners, Pocahontas met and married the colonist John Rolfe.
Well remembered Native American Indian leaders include Cochise (Apache) Geronimo (Apache) and Sitting Bull (Sioux).
Famous American outlaws include Jesse James, Billy the Kid and Butch Cassidy.
Oklahoma was a centre of the early cattle industry.
Over the years immigrants arrived in the USA from all over the world: China, France, Germany, Holland, Hungary, Ireland, Italy, Japan,
Mexico, Poland, Portugal, Puerto Rico, Sweden, Spain and Vietnam.
Richmond, the capital of the state of Virginia in the USA, was named after Richmond upon Thames in the UK.
The State of Nevada's name comes from the Spanish meaning snow-capped.
The State of Louisiana was named after the French King Louis XIV.
Henry Wadsworth Longfellow wrote Paul Revere's Ride. The poem tells the story of the ride through the country to alert people to the beginning of the American War of Independence:
"The fate of a nation was riding that night;
And the spark struck out by that steed, in his flight,
Kindled the land into flame with its heat."
George Washington was the first President of the United States.
The American Colonization Society promoted resettling freed American slaves in Africa. The resettlement of freed slaves in Liberia began in 1822.
President Abraham Lincoln was shot while attending the theatre with his wife. He died the following morning on 15 April 1865.
Between 1927 and 1941, Gutzon Borglum sculpted busts of Presidents George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln on Mount Rushmore.
Russia sold the State of Alaska (to the west of Canada) to the United States in 1867.
Frederic Auguste Bartholdi was the sculptor of the Statue of Liberty and Gustave Eiffel its structural engineer. The statue was presented to the American people by the people of France on 4th July 1884 and shipped to the US in early 1885.
Al Capone, one of America's most famous gangsters, made his money selling alcohol during Prohibition (anti-alcohol laws).
Helen Keller was born in Alabama in 1880 and lost her sight and hearing at a very early age. Helen grew up to become a famous speaker who also helped to set up the American Foundation for the Blind.
In 1903 the Wright brothers made the first successful flight in a plane.
Lindburgh made the first non-stop transatlantic flight from New York to Paris in 1927.
Amelia Earhart was the first woman to fly the Atlantic (1931).
New York's Empire State Building, a National Historic Landmark, is one of the world's tallest buildings.
Buckingham Fountain in Grant Park on Lake Michigan is among the world's largest fountains and one of Chicago's most familiar landmarks.
William Randolph Hearst (1863-1951) was an American newspaper owner who is said to have inspired Citizen Kane, the film directed by Orson Welles.
Jean Paul Getty (1892-1976), the American oil baron, set up a foundation dedicated to the visual arts and the humanities.
During the Second World War in August 1945 the USA dropped the Atomic Bomb on Japan in Hiroshima and Nagasaki.
The Polaris atomic-powered submarines were launched in 1958. They were armed with nuclear warheads and had a very long firing range.
In 1960 a US reconnaissance plane was shot down over the USSR. Its pilot, Gary Powers, was captured but later released.
Malcolm X, the black militant leader, was shot and killed in 1965.
1968 saw the death of Martin Luther King, the Civil Rights leader, aged 38. He was awarded the Nobel Peace Prize in 1964.
The Anti-Vietnam War Movement in the US gained momentum in the late 1960s and early 1970s; the Americans withdrew from Vietnam in 1973.
Carl Bernstein and Bob Woodward were Washington Post reporters who investigated the Watergate break-ins. President Nixon ordered a cover-up of the affair and eventually had to resign.
On 18 May 1980 the Mount St Helens volcano (Washington State) erupted. Fifty-seven people and thousands of animals perished.
In 1986 seven members of the crew of the Challenger Space Shuttle were killed when the Challenger exploded just over a minute after take-off.
The Hubble Space Telescope was launched in 1990 to study stars and galaxies.
On 11 September 2001 four US planes were hijacked by terrorists; two crashed into the twin towers of the World Trade Center, one crashed into the Pentagon and the fourth crashed in a field in Pennsylvania. It was estimated that around three thousand people were killed.
In August 2005 Hurricane Katrina swept through the Gulf Coast of the USA killing thousands of people, destroying homes, property and infrastructure.
On 4 November 2008 Barack Obama was elected 44th President of the United States of America. Barack Obama is the first African-American to be elected President of the USA.
In May-June 2010 the Deepwater Horizon oil rig disaster in the Gulf of Mexico caused the United States' biggest oil spill.