Skip to main content

This Day in American History

September 17

1 historic event on this date

Founding1787

Constitution Signed

Delegates to the Constitutional Convention signed the completed Constitution in Philadelphia. The document would then go to the states for ratification.

Why It Matters

The signing of the Constitution marked the creation of the framework for American government that continues to this day. September 17 is now celebrated as Constitution Day.

Explore the Principles Behind the History

Every event in American history connects to the founding principles. Discover the ideas that shaped these moments.

View the 28 Founding Principles