Harvard academics have discovered a second parchment copy of the Declaration of Independence at a records office in southern England.

The only other parchment copy is on display at the National Archives in Washington, DC, researchers Emily Sneff and Danielle Allen have said in a statement to the Boston Globe.

The newly discovered document has been dated to the 1780s and was found in the town of Chichester's archives.

Harvard academics have discovered a second parchment copy of the Declaration of Independence at a records office in southern England

'I was just looking for copies of the Declaration of Independence in British archives,' Sneff told the Guardian.

She became excited when she saw that the listing mentioned parchment - which suggests a special document and not a simple copy.

'I reached out to them a bit skeptically,' Sneff said. 'The description was a little vague but once we saw an image and talked to a conservator we started to get excited.'

'I was on pins and needles,' Allen recalled to the New York Times.

'I thought we would turn it over and the back would say, 'Ha, ha, we fooled you!' '

It is believed to have originally belonged to the Duke of Richmond, or the 'Radical Duke,' (pictured) who left behind a legacy of advanced views on parliamentary reform

It is believed to have originally belonged to the Duke of Richmond, or the 'Radical Duke,' who left behind a legacy of advanced views on parliamentary reform.

'It would be nice to associate this document with the radical duke,' Sneff said.

During the Revolutionary War he gave significant support to the Americans, reported the Globe.

The document was most likely created in New York or Philadelphia, and researchers are trying to determine who wrote it and paid for it to be copied.

It is not an official government document, like the original, but a display copy likely created by a commercial clerk in the 1780's, reported the New York Times.

They believe that the document was probably commissioned by James Wilson of Pennsylvania.

HOW DID THE SECOND COPY END UP IN ENGLAND? The rare second parchment was found at the West Sussex Record Office in Chichester. Copies of the declaration made their way to England after the original 1776 signing. But the Sussex Declaration was made sometime in the next decade. Experts are still working to understand how the manuscript ended up in Britain. They believe it came from a law firm connected with the dukes of Richmond. Theorists think it was passed down to Charles Lennox, the third Duke of Richmond, by Thomas Paine - an American political activist who was one of the Founding Fathers. Lennox was a peer of George III and was called 'the radical duke' because he supported American colonists in their rebellion against the king and parliament. The document was moved to West Sussex in 1956. Advertisement

The signatories on the Sussex version of the document are not broken down by state, unlike the National Archives copy, researchers said.

Instead, the 56 signatures were done in a seemingly random order, which, researchers argue points to Wilson.

The copy is, otherwise, strikingly similar in appearance to the 1776 version.

Their team is working with British officials to test the document in the safest way possible so as to not damage the parchment.

Wilson worked with others on the original draft of the Constitution, and was one of the first justices appointed to the Supreme Court.

'The team hypothesizes that this detail supported efforts, made by Wilson and his allies during the Constitutional Convention and ratification process, to argue that the authority of the Declaration rested on a unitary national people, and not on a federation of states,' the researchers wrote in a statement to the Globe.

They believe that Wilson wanted to influence the debate over the Constitution, which is why he had the copy made, and could help to answer the question at the core of American politics regarding whether or not the country was founded by a united nation of people or a collection of states.

Wendy Walker, West Sussex County archivist, told MailOnline: 'We are looking forward to seeing the results of the hyperspectral imaging work and other analyses later in the summer.

'We are delighted to be working with Harvard, the Library of Congress and the British Library to find out more about this fascinating document and welcome this interest in the West Sussex archives.'