John Hancock was a Whig leader in Boston prior to the Revolutionary War, and went on to be the President of the Second Continental Congress - which was responsible for creating the Declaration of Independence. All very impressive. But most impressive of all was that his name would live on to be slang for 'signature'. Now that's a legacy. One day I imagine "Shaun" will be used by children to describe a world-weary sneer. I can but dream.
Hancock was born in Massachusetts, the son of a Reverend, but his father died when he was young, and John was sent to live with his Uncle in Beacon Hill. Thomas Hancock ran a prosperous shipping business, which John inherited when his uncle died in 1764.
Hancock was a noted businessman, and probably made at least some of this money smuggling - which he was tried for in 1768, though he was never convicted. He joined the Patriot cause after the Stamp Acts were imposed in 1764. He went on to be one of the instigators of the Tea Party. In fact, after the revolution began, he was such a well-known rebel that when the Boston Governor offered clemency to anyone who would lay down their arms, Hancock was specifically left out of the deal.
Hancock is probably best known for signing the Declaration of Independence; his signature was the first on the document. Possibly because of that - and possibly because Hancock was known for being extravagant - his name is signed with a flourish, written larger than any of the others. So now in America, your signature is sometimes referred to as "your John Hancock".
I needn't explain why to some people, that sounds a little bit dirty!
But I will: it sounds like a penis reference.