WASHINGTON — Preservation scientists at the Library of Congress have discovered that Thomas Jefferson, even in the act of declaring independence from England, had trouble breaking free from monarchial rule.

In an early draft of the Declaration of Independence, Jefferson wrote the word "subjects," when he referred to the American public. He then erased that word and replaced it with "citizens," a term he used frequently throughout the final draft.

The Library released news of the struck word for the first time Friday.

Fenalla France, a research chemist at the Library, said her lab made the discovery last year by using hyperspectral imaging, using a high-resolution digital camera that compiles a series of images to highlight layers of a document. Some of those invisible layers - like erased text and even fingerprints - pop into view on a computer screen.

France said it appears Jefferson used his hand to wipe out the word "subjects" while the ink was still wet. A distinct brown smudge is apparent on the paper, although the word "subjects" is not legible without the help of the digital technology.

"This has been a very exciting development," France said, calling the findings "spine-tingling."

Historic, handwritten documents reveal clues about the past that word processors cannot illuminate, said James Billington, librarian of Congress.

"It shows the progress of his mind. This was a decisive moment," Billington said. "We recovered a magic moment that was otherwise lost to history."

Accompanied by police escort, the document was unveiled outside its protective case for the first time in 15 years Friday morning for a demonstration of the hyperspectral imaging technology. It normally can only be viewed through a 130-pound oxygen-free safe.

The rough draft was written on two sheets of white legal-sized paper, on both the back and front sides of the sheets. It includes handwritten corrections by John Adams and Benjamin Franklin.

Later Friday, the document was returned to the library's vault.