Who sent the olive branch petition to the king?

The Quakers in Pennsylvania refused to support any declaration of independence unless the Congress first attempted to resolve the situation peacefully. The Quakers were very influential and managed to get a majority of Congress to agree to send a polite note pleading for peace and negotiation. (The King's response was to angrily denounce the Congress and call for execution of anyone associated with the independence movement.) The King definitely did not want the Olive Branch. The Olive Branch Petition did apparently have an influence on some in Parliament, who continued to make pleas to the King for the next 5 years while the war raged on.