Lost since a Union soldier stole it from the North Carolina state house in the waning days of the Civil War, an original handwritten copy of the Bill of Rights was recovered in a sting operation by FBI agents yesterday in Philadelphia, the city where the document first came into existence more than 200 years ago.

The faded document of vellum parchment had been passed from hand to hand for nearly 140 years but did not appear too worse for the wear. It is worth perhaps $40 million, though, in any real sense of the word, it's priceless.

"It's inconceivable that there could be a more important document in American history," said Joseph Torsella, president of the National Constitutional Center, the soon-to-open museum in Center City Philadelphia.

The FBI learned about the document after a broker got in touch with Torsella's museum a few months ago and offered to sell it. Torsella thought at first that this was the long-missing Pennsylvania copy. Five of the original 13 states have lost their copies of the Bill of Rights over the years. But as members of his staff held more talks, and investigated the claims, they came to understand that this was the missing North Carolina copy.

At this point, the museum contacted North Carolina officials and the FBI. An FBI agent posing as a philanthropist met on Tuesday with a broker representing the seller, who demanded $4 million -- a tenth of the document's value. They met at the law office of Stephen Harmelin, who represents the National Constitution Center.

"A courier appeared with this document in a cardboard box, if you can believe that," Jeffrey A. Lampinski, the FBI special agent in charge of the Philadelphia office, said at a noon news conference in Philadelphia.

The FBI has not made any arrests, and officials said the civil seizure warrant has been sealed by court order. The investigation is ongoing.

The faded but still legible document, written in sepia-colored ink, is not, strictly speaking, a copy. In 1787, the Constitutional Congress passed the Constitution and sent it out to the states for ratification. Then, at the demand of the anti-federalists who feared an over-powerful central government, Congress agreed in 1789 to draw up the Bill of Rights -- the first 10 amendments to the Constitution. President George Washington directed that three scribes write 14 copies by hand. One was kept by the federal government, and the others were sent to each of the 13 original states. Those copies were to be ratified by each state.

Five of those original handwritten documents are missing -- one of those is known to have been destroyed.

The recovered North Carolina document contains 12 amendments -- the first two, governing congressional pay raises and reapportionment, were subsequently struck from the document.

The Union soldier grabbed the copy as he marched south through North Carolina with Gen. William T. Sherman in 1865. The soldier took it home to his native Tippecanoe, Ohio, and apparently sold it a year later. Every 30 years or so, one owner or another tried to sell it back to North Carolina, always through intermediaries.

But North Carolina officials refused each time, insisting that they would not purchase back what was stolen from the state. "North Carolina's stolen Bill of Rights has been out of state for nearly 140 years but never out of mind," North Carolina Gov. Mike Easley (D) told the Associated Press. "It is a historic document, and its return is a historic occasion."

"It's inconceivable that there could be a more important document in American history," Joseph Torsella of the National Constitutional Center in Philadelphia says of the U.S. Bill of Rights.