U.S. Constitution Signed
Delegates to the Constitutional Convention signed the United States Constitution, creating the framework for the federal government that has governed the nation for over 235 years.
What Happened
From May to September 1787, delegates from twelve states met in Philadelphia for the Constitutional Convention. What began as a meeting to revise the Articles of Confederation became a complete replacement. The Constitution created three branches of government with a system of checks and balances, established a stronger federal government while preserving significant state powers, and included the three-fifths compromise counting enslaved people for representation and taxation. Thirty-nine of forty-two delegates present signed the document on September 17. Ratification by nine states was required; New Hampshire became the ninth in June 1788.
Why It Mattered Then
The Constitution solved the fundamental problem of the Articles of Confederation: a national government too weak to function. It created a durable framework for federal authority while embedding protections against tyranny through separation of powers, bicameralism, and federalism.
Why It Matters Now
At over 235 years old, the U.S. Constitution is the world's longest-serving national constitution still in use. It has been amended 27 times. Its interpretation — particularly regarding individual rights, federal power, and equal protection — remains one of the most contested arenas of American political life.
Key Themes
This event is part of the 1783–1791: Constitution and Bill of Rights era (1783–1791).
Explore This Era →