As the result of a historic agreement between the New York Public Library and the State of Pennsylvania, the National Constitution Center will exhibit one of the original copies of the Bill of Rights that President George Washington dispatched to the states in 1789 for ratification.

Pennsylvania and the library will jointly care for and display the document for the next century. Announcement of the agreement is set for a Wednesday news conference at the center on Independence Mall.

"This is a win for Pennsylvania, New York, and the citizens of the United States," Gov. Corbett said in a statement, noting that the document will now be shown to the public "for the first time in decades."

The Bill of Rights constitutes the first 10 amendments to the Constitution. They safeguard fundamental individual and civic freedoms, such as freedom of speech, press, and religion, and prohibit unwarranted governmental intrusions into private and social life.

The agreement is unusual in many ways, perhaps chiefly because many scholars believe the copy that has been in the New York library's archives since the late 19th century most likely belongs to Pennsylvania.

"The widely held belief is that in the mid- to late 1800s, there was a guy who was systematically stripping the Commonwealth of Pennsylvania of important historic documents and selling them in New York City," said lawyer Stephen Harmelin, a trustee of the Constitution Center who conducted negotiations with the library and New York state officials for more than six years before the sharing arrangement was reached.

The stolen copy was probably sold to a New York collector, scholars believe, and was donated to the public library in 1898.

But "widely held belief" is one thing, proof in a court of law another. "It's pretty hard, 100 years later, to prove something like that," said Harmelin, cochairman of Dilworth Paxson L.L.P., who approached New York officials.

"What we said was, 'Look, all we want to know is, is this ours?' Then their counsel said, 'It's not good enough to conclude simply that the document may or may not have originated in Pennsylvania. If you're asserting a legal position, then you also have to demonstrate that it unlawfully left Pennsylvania.'

"There's an interesting challenge - prove that a document that's been missing 100, 200 years did or did not leave Pennsylvania with authority."

In the end, Pennsylvania and New York agreed to set aside the issue of ownership and work out joint stewardship. As a result, the Constitution Center will begin exhibiting the document in 2014 for three years. Other venues in the state will be allowed to show it as well if they meet standards for security and exhibition.

The New York library last displayed the document many decades ago and has never shown it for an extended period because of preservation concerns, officials said.

Jeffrey Rosen, just named president and CEO of the Constitution Center, hailed the agreement as "a milestone."

For Harmelin, it marks a satisfying conclusion to a quest going back more than a decade. In fact, almost exactly 10 years ago, Harmelin believed the center was about to acquire its very own Bill of Rights from a antiques dealer.

But instead of buying the document, Harmelin and then-center president Joe Torsella agreed to participate in an FBI sting to capture the seller. That copy now resides in North Carolina - where it started out in 1789.

Georgia, Maryland, New York, and Pennsylvania are all missing the copies sent out by Washington and signed by Vice President John Adams in 1789. (There were 14 original copies - one for each state and one for the federal government.)

There are two more-or- less-unidentified copies - the one in the New York Public Library that is subject to the agreement between New York and Pennsylvania, and a copy held by the Library of Congress.

New York's original copy most likely burned in an Albany fire in 1911.

The copy belonging to the Library of Congress was acquired in the 1940s in a sale brokered by Philadelphia's renowned collector, A.S.W. Rosenbach. The document "had to be stolen property," author David Howard notes in his book, Lost Rights.

Twists and turns aside, Harmelin, the Constitution Center trustee, is elated about the New York-Pennsylvania agreement. Not only is the ownership issue off the table, but an essential American document will now be exhibited just blocks from where it was first discussed in Independence Hall more than two centuries ago.

"I cannot think of a historic document more important to Pennsylvania than the document that binds every Pennsylvanian to the federal government, to America," he said. "This is the bridge that makes you not only a Pennsylvania citizen, but an American citizen."

Contact Stephan Salisbury at 215-854-5594, ssalisbury@phillynews.com, or @SPSalisbury on Twitter.