In 1972, Richard Nixon was running for reelection. Nixon Had a shady group of characters working for called the Committee to Reelect the President (CREEP) and many of the members were part of his administration or close personal associates. Officially it was a fundraising organization, but really they engaged in a number of illegal activities like money laundering, political intimidation...etc

The headquarters of the Democratic Party (Nixon was a Republican) were in the Watergate Complex in Washington D.C. Members of CREEP broke into the Democratic Party offices to steal documents and plant bugs. They were caught. Over the next 2 years, it became clear through whistle blowers, testimony at the trials of CREEP members, and the revelation of secret audio tapes that Nixon kept of conversations he had in the oval office, that Nixon was personally involved in covering up his administration's involvement with the break in and sabotaging official investigations into it. Facing almost certain impeachment and removal from office, Nixon chose instead to resign.