One of 11 surviving copies of ‘Exeter printing’ and only one known outside US was taken from American privateer ship

For Michael Scurr, a volunteer at the National Archives in Kew, west London, it was “just a boring old Thursday morning” when he sat down in late May to catalogue a collection of documents from the British national collection that had never previously been recorded in detail.

As he opened a volume of 18th-century Royal Navy correspondence, however, Scurr unfolded a document whose opening words he recognised. “In Congress, July 4, 1776. A declaration by the representatives of the United States of America …”