Archibald Cox, the special prosecutor who was appointed by Congress to investigate the events surrounding the Watergate break-in of June 17 ,1972, had earlier issued a subpoena to U.S. President Richard Nixon, asking for copies of taped conversations which Nixon had made in the Oval Office as evidence. Nixon initially refused to comply with the subpoena, but on October 19, 1973, he offered what was later known as the Stennis Compromise, asking a U.S. Senator to review and summarize the tapes for the special prosecutor's office. Cox refused the compromise that evening, and it was believed that there would be a short rest in the legal maneuvering while government offices were closed for the weekend.
However, President Nixon acted to dismiss Cox from his office the next night. He contacted Attorney General Elliot Richardson and ordered him to fire the special prosecutor. Richardson refused, and instead resigned in protest. Nixon then ordered Deputy Attorney General William Ruckelshaus to fire Cox; he, too, refused and resigned.
Nixon then contacted the Solicitor General, Robert Bork, and ordered him as acting head of the Justice Department to fire Cox. Bork complied.
Congress was infuriated by the act, which was seen as a gross abuse of Presidential power. In the days that followed, numerous bills of impeachment against the President were introduced in Congress. Nixon defended his actions in a famous press conference on November 17, 1973, in which he said, "...in all of my years of public life, I have never obstructed justice. And I think, too, that I should say that in my years of public life that [sic] I've welcomed this kind of examination, because people have got to know whether or not their President's a crook. Well, I'm not a crook!"
The Independent Counsel Act, passed in 1978, was a direct result of the Massacre.