I love this letter from Abraham Lincoln:

One day . . . I got into a fit of musing in my room and stood resting my elbows on the bureau. Looking into the glass, it struck me what an ugly man I was. The fact grew on me and I made up my mind that I must be the ugliest man in the world. It so maddened me that I resolved, should I ever see an uglier, I would shoot him on sight. Not long after this, Andy [naming a lawyer present] came to town and the first time I saw him I said to myself: ‘There’s the man.’ I went home, took down my gun, and prowled around the streets waiting for him. He soon came along. ‘Halt, Andy,’ said I, pointing the gun at him, ‘say your prayers, for I am going to shoot you.’ ‘Why, Mr. Lincoln, what’s the matter? What have I done?’ ‘Well, I made an oath that if I ever saw an uglier man than I am, I’d shoot him on the spot. You are uglier, surely; so make ready to die.’ ‘Mr. Lincoln, do you really think that I am uglier than you?’ ‘Yes.’ ‘Well, Mr. Lincoln,’ said Andy deliberately and looking me squarely in the face, ‘if I am any uglier, fire away.’

There are several other funny letters from famous people at:
www.wnyc.org/books/15539