A rare copy of the American Declaration of Independence found by volunteering in UK archives

Following restoration work, the replica will be on display at the Archives exhibit at America’s Freedom Trail, which opened last month.

Saul Nasse, chief executive of the National Archives, hailed the discovery as an “extraordinary find”.

He added: “This is one of the rarest surviving copies of the Declaration of Independence found here in the UK, not in America.”

The document was captured by the Royal Navy on Christmas Eve 1776 when HMS Reasonable captured the American ship Dalton off the coast of Portugal during a seven-hour pursuit.

Dr Graham Moore of the National Archives said the find was “one of the rarest forms of advertising we know of” and had not been preserved for the sake of quick circulation.

“After its initial publication on July 4, news of the announcement traveled rapidly across North America and was being reprinted as it reached each successive colony,” he told the BBC.

“The copy we have is one of only 11 surviving first editions in New Hampshire.”