The last time the Magna Carta travelled abroad was 20 years ago

Lincoln is home to one of only four copies of the 792-year-old document, signed by King John and detailing the rights of the sovereign.

Magna Carta became an iconic symbol of freedom, influencing many common law documents, such as the United States Constitution and Bill of Rights.

Lincoln's copy will go on display in America in March.

Bitter infighting

It has spent months with the city's conservation department, being examined by a parchment specialist to ensure it will not be damaged while it is on its travels.

The last time the Magna Carta travelled abroad was 20 years ago. That trip to Australia lost Lincoln Cathedral more than �50,000 and led to bitter infighting among senior clergy.

Roy Bentham from the cathedral said the organisers of the American trip had been told to put in place safeguards to ensure it was a success.

"The first was make sure that all the funds are in place before you go, which we've done.

"The second was be careful of any commercial spin-off activities. We won't be doing any commercial things over there, so the risk is minimal."