What is the oldest active written national constitution in the world?

The U.S. Constitution is recognized as the oldest active written national constitution in the world, having been adopted in 1787 and coming into effect in 1789. It established a framework for the government of the United States and has been the governing document for over two centuries, making it a significant historical and legal document.

Its endurance and adaptability, supported by the amendment process outlined in the document itself, contribute to its status. Although other countries have constitutions, many have been amended, replaced, or restructured multiple times throughout history, whereas the U.S. Constitution remains fundamentally intact, with only 27 amendments having been made over its lifetime.

This unique aspect of the U.S. Constitution highlights its role in shaping governance and legal practices in various democracies around the world, often serving as a model for other nations.