
Although he states otherwise in this incredible document, Fidel Castro was just 14-years-old when he wrote and sent it to then-President of the United States, Franklin D. Roosevelt. In it, the future Cuban leader speaks of his approval of Roosevelt's presidency, cheekily asks the President for $10, and then finishes the letter by offering to reveal the whereabouts of Cuba's largest iron mines.
Transcript follows.
(Source: Wikimedia; Image: Fidel Castro, via.)

Transcript
Santiago de Cuba
Nov 6 1940
Mr Franklin Roosvelt, President of the United States.
My good friend Roosvelt I don't know very English, but I know as much as write to you. I like to hear the radio, and I am very happy, because I heard in it, that you will be President for a new (periodo). I am twelve years old. I am a boy but I think very much but I do not think that I am writing to the President of the United States. If you like, give me a ten dollars bill green american, in the letter, because never, I have not seen a ten dollars bill green american and I would like to have one of them.
My address is:
Sr Fidel Castro
Colegio de Dolores
Santiago de Cuba
Oriente Cuba
I don't know very English but I know very much Spanish and I suppose you don't know very Spanish but you know very English because you are American but I am not American.
(Thank you very much)
Good by. Your friend,
(Signed)
Fidel Castro
If you want iron to make yoursheapsships I will show to you the bigest (minas) of iron of the land. They are in Mayari Oriente Cuba.