The exhibit, "Creating the United States," uses interactive computer screens to display drafts of the Constitution, the Bill of Rights and other historic documents.

The exhibit allows visitors to see how the documents evolved. The Declaration of Independence, for instance, initially read "We hold these truths to be sacred and undeniable, that all men are created equal."

But Benjamin Franklin changed it to read "We hold these truths to be self-evident." Franklin felt that the initial wording made the declaration sound too religious.

The high-tech offerings are a big leap for the world's largest library, which is trying to give visitors more ways to access its books, documents, audio and film resources.