One of only two parchment copies of America’s Declaration of Independence has been discovered in a record office in West Sussex, filed away without fanfare for half a century.

Researchers from Harvard University were shocked to unearth the manuscript while compiling a database of later reproductions of the declaration. The only other parchment manuscript copy is kept in the National Archives in Washington DC.

According to the researchers, staff at the West Sussex Record Office, in Chichester, had not taken a particular interest in the copy, which was produced ten years after the declaration, before the team from Harvard got in touch. They are now said to be “working on a valuation”.