United States federal government continuity of operations
The Continuity of Operations Plan (or Continuity of Government) is a shadow government conceived by the Eisenhower Administration during the Cold War to ensure the executive branch of the U.S. government would be able to continue in case of nuclear war.
The George W. Bush Administration put it into effect for the first time directly following the September 11, 2001 Terrorist Attack. Their implementation involves a rotating staff of 75 to 150 senior officials and other government workers from every Cabinet department and other parts of the executive branch in two secure bunkers in the East Coast. Friends, family and co-workers can only reach them through a toll-free number and personal extensions.
The Bush Administration officially admitted the implementation of the plan on March 1, 2002.