A RARE, handwritten copy of the US Declaration of Independence has been unearthed.

Hidden away in the West Sussex Record Office in Chichester, it is only the second known parchment manuscript of the historic document.

The original, signed in Philadelphia on July 4, 1776, and on display at the National Archives in Washington, proclaimed the then 13 American colonies were free from British rule.

Harvard researchers Emily Sneff and Danielle Allen made the discovery while compiling records for a database and dubbed it the Sussex Declaration.

The parchment is the same size as the original Declaration but has been written horizontally and is believed to have been created in the US in the 1780s.

The Sussex Declaration also dispenses with state-by-state groupings for the list of signatories, whose names were written, with some misspelt, by a single clerk.

Federalist and Supreme Court Justice James Wilson, one of six men to sign both the Declaration and the Constitution, is thought by the researchers to be the “likeliest candidate” behind the creation of the copy.

He was known for supporting the argument that the US was founded by its people and not by a confederation of states, which the researchers hypothesise is the reason for the jumbled signatories.

Professor Allen said: “Up until now only one large format ceremonial parchment manuscript was known to exist.

“That one is in the National Archives and was produced in 1776.

“This one was produced a decade later with the signed parchment as its source, as part of the fight between federalists and anti-federalists about whether the new republic was founded on the authority of a single, united sovereign people or on the authority of 13 separate state governments.

“The federalists were making the first argument and this document appears to have been produced to support their case.

Researchers are now trying to solve the mystery of how the Sussex copy of the declaration ended up in the county.