On July 4 1826 both John Adams and Thomas Jefferson died, precisely 50 years after signing the Declaration of Independence. The only surviving signer was Charles Carroll. On July 4 1862 Lewis Carroll first told the tale of Alice's Adventures in Wonderland to Alice Liddell.
"Lewis Carroll and Douglas Adams,"
Word Ways: Vol. 38
, Article 6.
Available at: http://digitalcommons.butler.edu/wordways/vol38/iss1/6