Anthrax attacks, in the form of letters carrying the bacteria posted to journalists and politicians, begin in the USA

Describing September 11 as an act of war, President Bush retaliates with a 'War on Terrorism'

US President George W. Bush revives bitter memories in the Middle East when he describes the war on terrorism as a 'crusade'

The giant Texas energy company Enron files for bankruptcy after disclosure of major accountancy fraud

The US space shuttle Columbia disintegrates, with seven on board, when re-entering the earth's atmosphere

US tennis player Pete Sampras retires with a record total of 14 Grand Slam titles

Californians vote to remove governor Gray Davis from office in a 'recall' election and to replace him with Arnold Schwarzenegger

US singer Britney Spears creates a new record when she has a fourth successive album (In the Zone) go straight to the top of Billboard 200

George W. Bush wins a second term, defeating Democrat John Kerry in the US presidential election

A student at Red Lake High School in Minnesota kills five fellow students and two staff members before committing suicide

After a long trial US singer Michael Jackson is declared in a California court not guilty on ten charges of child molestation

Hurricane Katrina brings flooding and chaos to New Orleans and other coastal areas, causing more than 1500 deaths

The US Supreme Court rules that the military courts set up to try detainees in Guantanamo Bay are illegal

A milk-truck driver opens fire on children in an Amish school in Pennsylvania, killing five girls and wounding others

Google pays $1.65 billion for the website YouTube, launched less than two years previously

The United States Census Bureau announces that the US population has reached 300 million

The Republicans lose control of both houses of the US Congress in an electoral backlash against the Iraq War

Stores open in the US state of Colorado freely selling 'recreational' cannabis, under a new state law

Supporters of cattle rancher Cliven Bundy and law enforcement confront each-other following a 21-year legal dispute in which the United States Bureau of Land Management (BLM) obtained court orders directing Bundy to pay over $1 million in withheld grazing fees for Bundy's use of federally owned land.

The shooting of Michael Brown, an African American, by a police officer occurs in Ferguson, Missouri triggering riots.

The uncrewed Rosetta spacecraft's Philae probe successfully lands on Comet 67P, the first time in history that a spacecraft has landed on such an object.

NASA's Dawn probe enters orbit around Ceres, becoming the first spacecraft to visit a dwarf planet

NASA's New Horizons spacecraft performs a close flyby of Pluto, becoming the first spacecraft in history to visit the distant world.

Gravitational waves are detected for the first time, by LIGO

NASA announces that liquid water has been found on Mars