Its history is marked by many important inventions that changed the world, including the concept of time, math, the wheel, sailboats, maps and writing. Mesopotamia is also defined by a changing succession of ruling bodies from different areas and cities that seized control over a period of thousands of years.
Not only was Mesopotamia one of the first places to develop agriculture, it was also at the crossroads of the Egyptian and the Indus Valley civilizations. This made it a melting pot of languages and cultures that stimulated a lasting impact on writing, technology, language, trade, religion, and law.
The president vetoing a bill from Congress. Congress overruling that veto with a 2/3rds vote. The Supreme Court striking down a law as unconstitutional.