Which nation has the longest-standing written constitution of all nations in the world?
Per the Encyclopedia Britannica, the Constitution of the United States of America is the "oldest written national constitution in use" anywhere in the world. The U.S. Constitution is the supreme legal authority in the United States. It is the written pact that established the U.S. federal government and vested it with certain powers. All Presidents, governors, and federal/state judges and legislators are "bound by Oath or Affirmation, to support" it.