Who is famous for the "free consent of the people" idea?
It seems that it was Thomas Hooker from the colony of Connecticut who first came up with the phrasing of the idea of free consent of the governed. I have found a couple of sources to verify that Hooker spoke out at a hearing of the Connecticut court during a yearly election.
The foundation of authority," said Hooker, in an election sermon preached before the general court, on the last day of May, 1638, "is laid in the free consent of the people, to whom the choice of public magistrates belongs by God's own allowance." (From http://vftonline.org/EndTheWall/consent.htm)
Clearly this was an idea that influenced the founding fathers when they drafted our constitution.
It is actually a remarkable idea if you think about it, that people can agree to be governed. Before then, it was whoever had the power who made the decisions.