On June 17, 1972, five men, including a former CIA employee, were arrested while trying to bug the offices of the Democratic National Committee at the Watergate hotel and office complex in Washington, DC.
The incident occurred about three months before the American presidential election, in which Richard Nixon, the sitting Republican president, was widely expected to rout his Democratic rival. Which is why the break-in was mysterious.
Most American newspapers, including The New York Times, treated it as a routine crime, but
two young The Washington Post reporters grabbed the story by the throat and exposed the biggest scandal to rock America in the 20th century, eventually forcing Nixon to resign two years later, on August 8, 1974.
Bob Woodward and Carl Bernstein -- or Woodstein, as they were known in newsrooms around America -- were greatly assisted in their journalistic endeavour by an anonymous source, later nicknamed Deep Throat.
For over 30 years, people have speculated about the identity of Deep Throat.
Virtually everyone who served in the Nixon administration was considered a contender, but Woodward and Bernstein refused to divulge their source's identity, insisting they had pledged to keep it a secret till Deep Throat was dead.
Deep Throat's identity was thus the best kept secret in America until Vanity Fair magazine identified 91-year-old W Mark Felt, a former associate director of the Federal Bureau of Investigation, as the long-anonymous source.
This was confirmed by Felt and the Washington Post on May 31, 2005.
Mark Felt waves at the door of the US district court in Washington, DC, April 20, 1978 before entering to be arraigned on a grand jury charge of one count of conspiring to violate citizen rights.
Photographs: AP Photo/Bob Daugherty