September 17 marks the annual celebration of Constitution Day, commemorating the date on which 39 of the Philadelphia Convention’s delegates signed the Constitution in 1787. This year, it will be observed on September 16, and will include forty federal judges across the country swearing in new citizens during special naturalization ceremonies held at national historic landmarks. Chief Judge Robert A. Katzmann, of the U.S. Court of Appeals for the Second Circuit, will preside at an Ellis Island ceremony.

Constitution Day was created in 2004 to encourage public schools and governmental offices to promote a better understanding of the Constitution, the world’s longest surviving written charter of government.

The original document is held at the National Archives in Washington, D.C. You can read the Constitution online, or pick up your own pocket-copy at the library’s reference desk! For deeper coverage, you can also download the Library of Congress’s free app containing the official, annotated version of the United State Constitution, U.S. Constitution: Analysis and Interpretation.

For more information about the day, visit the National Constitution Center’s web site.