A most significant worldwide, forgotten 200th birthday is that of the United States (of America): born on November 15, 1777.
The Second Continental Congress approved the "Articles of Confederation" for ratification by the States on November 15, 1777, after a year of debate.
In practice, the final draft of the Articles served as the de facto system of government used by the Congress ("the United States in Congress assembled") until it became de jure by final ratification on March 1, 1781; at which point Congress became the Congress of the Confederation.
The Articles set the rules for operations of the United States government.
See: Wikipedia (WikipediaŽ is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.) which is highlighted by Epsilon=One, at: www.CQthus.com/USBirthdayNov15