Oliver F. Atkins/White House photographer
1974: A grand jury in Washington, D.C., indicts several former aides of President Richard Nixon for conspiring to hinder the Watergate investigation. The former aides, H. R. Haldeman (left), John Ehrlichman (right), John N. Mitchell, Charles Colson, Gordon C. Strachan, Robert Mardian and Kenneth Parkinson, would become known as the "Watergate Seven." The grand jury also named Nixon an unindicted conspirator. The indictments marked the first time in U.S. history that a president was so named.