For most of America's time in the Second World War, they were led by Franklin D Roosevelt. But Roosevelt died early in 1945, and suddenly the handling of the closing stages for the war was handed to President Harry Truman.

It was Truman who finally authorised the use of nuclear weapons against Japan, and it was Truman who then negotiated her surrender. In this, the key document was the Potsdam Declaration, which declared the requirements for Japan to end the war.

The text, agreed by Truman, Winston Churchill and Chiang Kai Shek by telegraph, was stern, requiring not merely the renouncing any territory gained during the war, but all the territory back to pre-1894 levels. It also refers to 'unconditional surrender'.

This week, the only known complete text of the Potsdam Declaration, signed by Truman (as well as by him on behalf of Churchill and Chiang Kai Shek) is now up for sale at Alexander Autographs, with a listing of $10,000-150,000.

Potsdam Declaration of requirements for Japanese surrender

Although this is the highest valued document in the sale, it is not the only exceptional piece of interest to the Presidential autograph collector.

There is a pair of autographs relating to President Lincoln's assassination: one from his killer John Wilkes Booth which tells of the loss of his 'best friend' - a whiskey flask. He gave to a boy to look after, but they lost it, and Booth saw it destroyed himself:

"I returned within sight of the Fort, and judge of my dismay upon arriving to see a waggon just crushing my best friend, but I kissed him in his last moments by pressing the snow to my lips, over which he had spilled his noble blood."

Booth's letter is listed at $40,000-50,000, whilst one by his killer, Thomas P "Boston" Corbett, who shot Booth against orders to take him alive, is listed at $20,000-25,000. The letter is a reply to an admirer, detailing the circumstances of Booth's death.

A really fascinating piece of early Americana however is a secretive letter written by George Washington to close friend, John Fitzgerald (1756-1799) forwarding his response to "...the Resolution of the Citizens of Alexandria..."

That is, the letter refers to the question of American attitudes to the French Revolution, and its radical turn.

The issue had split America's political class as the ideals of that revolution were similar to America's own, but there was alarm at the turn matters were taking, especially when the French ambassador Genet turned up in America, and began openly licensing privateer attacks on British ships.

Washington's cabinet voted to expel Genet and remain neutral. The letter is listed at $60,000-80,000 in the sale which takes place on October 9 in Connecticut and online.

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