Happy Constitution Day: 5 facts about America's most important document

Happy birthday to the U.S. Constitution.

Each Sept. 17 marks Constitution Day, the anniversary of the day in 1787 when 38 founding fathers gathered in the Philadelphia building now known as Liberty Hall to sign the document that still guides America.

Every year, the National Constitution Center answers hundreds of questions about the document and the Founding Fathers from students. Here’s some facts about the constitution, taken from the center’s list of frequently asked questions:

Q: What is the Constitution?

A: The document that set the framework federal government system, including its structure and rights and freedoms protected against government interference.

Q: How long did it take to create the Constitution?

A: Drafting the document took about four months. It would take about nine more months to be ratified by the states.

Q: What was the average age of the delegates?

A: 42. The oldest was 81-year-old Benjamin Franklin. The youngest was 26-year-old New Jersey delegate Jonathan Dayton.

Q: Who wrote the Bill of Rights? When was it added?

A: James Madison. The Bill of Rights contains the first 10 amendments. It was added in December 1791.

Q: Why haven’t we had a Constitutional Convention in recent years ?

A: The Constitution allows Congress to call a convention to propose new amendments to the constitution, but such a convention has never been called. There are 27 amendments to the constitution (the Bill of Rights plus 17 others), but these were all added without a convention. Organizing one would be a complicated, years-long process.

The most recent amendment was passed by Congress in 1789 but not ratified by the states for more than 200 years. It was finally ratified in 1992. The 27th Amendment states that any pay raise Congress gives itself will not take effect until after the next election.