A volunteer at The National Archives in Kew has uncovered a “vanishingly rare” copy of the US Declaration of Independence dating to 1776. The finding was made in February while Michael Scurr was cataloguing papers from Royal Navy captains connected to the American Revolutionary War.

The document is an “Exeter Declaration,” one of 11 known surviving copies of that specific 1776 Exeter, New Hampshire printing. The National Archives says it is the only known copy outside the United States. The paper had been seized by the Royal Navy on Christmas Eve 1776 after the capture of an American ship, the Dalton, and it was kept among other seized papers simply as “another paper.”

After identification, the archives carried out conservation work to stabilize the document and repair a slight tear. Following restoration, it is set to be displayed in the archives’ Revolution 250 exhibition focused on America’s independence story.