Before the movie got its rating, it was under the Touchstone Pictures banner (which is part of Disney). When the film got its rating (which is PG), it was then put under the Walt Disney Pictures banner, as it is clear that it is a more family-friendly movie.
The movie suggests that something is written on the back of the Declaration of Independence. It is true that something is written on its back. The writing on the back of the Declaration of Independence reads: "Original Declaration of Independence dated 4th July 1776" and it appears on the bottom of the document, upside down. While no one knows for certain who wrote it, it is known that early in its life, the large parchment document (it measures 29 3/4 inches by 24 ½ inches) was rolled up for storage. So, it is likely that the notation was added simply as a label.
Ben, Patrick, and John Gates were all named after founding fathers (Benjamin Franklin, Patrick Henry, and John Adams). Abigail Chase is a combination of Abigail Adams, wife of John Adams, and Samuel Chase, a signer of the Declaration of Independence and later an Associate Justice of the United States Supreme Court.
The cities that the major action takes place in (Washington D.C., Philadelphia, and New York City) are three of the nine capital cities the United States has had in its history.
Along with the Gates family all being named after founding fathers, Ian's last name is Howe, the last name of two brothers who were a British general and an admiral in the Revolutionary War.
In the DC segment during the planning stage of the burglary the movie cuts to an external shot of a building on the Potomac River - presumably where the bad guys are planning their attempt. This building is the Watergate Hotel.
The water in the reflecting pool in front of the Abraham Lincoln Memorial in the scene where Ben and Riley are talking on the steps was digitally added later because the water drained for maintenance at the time of filming.
EASTER EGG: To see some hidden special features on the R2 DVD navigate to the logbook in the upper right corner of the main menu and press select to enter, then enter the code 405 and select the 'master code' for a list of all the special features available (some are otherwise only available in several hidden menus that must be found through mini-games on each menu).
When Gates is purchasing a replica Declaration of Independence in the gift shop, on the counter next to the register is a stack of books for sale. The book is 'The Secret Architecture of our Nation's Capital' by David Ovason and is about the Masons and the building of Washington DC. Ovason also wrote "Secret Symbols of the Dollar Bill", and US currency is used as one of the clues in the film.
When Ben is copying the encryption on the back of the declaration, the two numbers that he is actually shown writing are 7-4 and 7-2. July 2, 1776 is the date that the continental congress agreed upon independence from Britain and July 4 is the date that Thomas Jefferson's resolution was accepted and signed.
The book that Ben shows Riley in the Library of Congress that has the information about the Preservation Room is called 'The Earth System'. It is some sort of a textbook and it is authored by Lee Kump, James F. Kasting, and Robert G. Crane. The ISBN is 0131420593.
While Gates is attempting to decipher the first clue on board the Charlotte, after Shaw suggests "Prison," Riley says, "Albuquerque. See, I can do it too. Snorkel." This is a reference to the 1998 'Weird Al' Yankovic song, "Albuquerque," which talks about a man's journey to Albuquerque with his lucky snorkel.
On the yellow piece of paper, on which Ian (Sean Bean) was writing out the secret message contained on the pipe found on the "Charlotte", there was drawn, at the top of the page, two crossed swords with a circle between them. This drawing is the logo for Bean's hometown Football Club, Sheffield United known also as The Blades.
Sadusky wears a tie with the United States Marine Corps insignia during the film. Harvey Keitel who plays Sadusky served with the Marines prior to becoming an actor.
The Liberty Bell shown in the movie was actually made of styrofoam. The movie was shot a few days before the Liberty Bell was put in. This is proven by the fact that protective shades were installed in the observation window when the bell was installed. In the movie Ian looks exactly where the shades are supposed to be if the real bell was there.
Abigail Chase claims she's from Saxony in Germany when Gates first meets her. Diane Kruger is in fact from Germany, but from the state of Lower Saxony (Niedersachsen), not Saxony.
Benjamin Gates' apartment is #544, the address on Camp Street in New Orleans where conspiracy theorists believe John F. Kennedy's assassination was planned.