Newtown Battlefield State Park, formerly known as Newtown Battlefield Reservation, was the site of the Battle of Newtown fought in August 1779, during the American Revolutionary War. It was the only major battle of the Sullivan Expedition, an armed offensive led by General John Sullivan that was ordered by the Continental Congress to end the threat of the Iroquois who had sided with the British in the American Revolutionary War. In the battle, the Iroquois were defeated decisively.