Watergate was a political scandal that took place in the United States of America in the early 1970s. President Richard Nixon resigned because of his involvement.
Roberta Lincoln followed the Watergate scandal closely in 1974. (ST - The Eugenics Wars novel: The Rise and Fall of Khan Noonien Singh, Volume 1)
In 2369, Q commented to Vash that he thought Watergate was an example of "character" that Earth used to have. (DS9 episode: "Q-Less")