Hancock's father, a Congregationalist minister, died when he was a boy of seven, leaving his mother a destitute widow with three children, and he was adopted by his uncle, Thomas Hancock, a rich Boston merchant. John grew up to become the richest man in New England. He was also a successful lawyer, again following in his uncle's footsteps.
He was the third president of the Continental Congress 1775-77, when the Declaration of Independence was adopted, and thus became the first man to sign it, and was governor of Massachusetts for nine terms, dying in office.