Watergate and the Use of Executive Privilege

Where did "Executive Privilege" come from?

    The “Executive Privilege” debate started with George Washington and still continues today. In 1792 George Washington refused to give information about a disastrous battle against Native Americans in the Ohio River Valley to the courts.Since then almost every President has used a form of "Executive Privilege" while  In 1803 the Supreme Court acknowledged a need for certain privacy for the President in the Marbury vs. Madison case. There was no phrase “Executive Privilege” before Dwight Eisenhower coined the phrase in 1954 during his presidency.
"A constitutional question of the first importance, raised in more or less acute form in practically every administration from Washingtons's to Eisenhower's, is, singularly enough, still wide open. That question is the constitutional power of the executive to withhold information from the legislature. It seems to be no nearer settlement today than it was in 1792, when President Washington announced the right of the executive to exercise its descretion in comminticating executive documents requested by a committee appointed by the House of Representatives "to inquire into the causes of the failure of the late expedition under Major General St. Clair." "
      - Joseph W. Bishop, Jr. 1957

What is "Executive Privilege"

    “Executive Privilege” is based on Article Two of the constitution and the separation of powers. Presidents claim that because there is separation of powers they can refuse to give up or release certain information to other branches of Government or the public. Since the time of Thomas Jefferson and the Aaron Burr case in which he refused to give up documents to the Supreme Court,) every incidence of “Executive Privilege” has been decided to be legitimate or illegitimate by the circumstances of the specific event. Another reason that Presidents give for using “Executive Privilege” is public safety. This reason has not been used as much as separation of powers but is also acknowledged by the Supreme Court. There have been no laws or amendments to the constitution regarding this privilege but there have been multiple Judiciary subcommittees and hearings about it.