The Battle of Newtown was the only major battle of the Sullivan Expedition, an armed offensive led by Major General John Sullivan that was ordered by George Washington to end the threat of the Iroquois who had sided with the British in the American Revolutionary War. Opposing Sullivan's four brigades were 250 Loyalist soldiers from Butler's Rangers, commanded by Major John Butler, and 350 Iroquois and Munsee Delaware. Butler and Mohawk war leader Joseph Brant did not want to make a stand at Newtown, and instead proposed to harass the enemy on the march, but were overruled by Sayenqueraghta and other Indigenous war leaders.

The 1779 Sullivan Expedition was a United States military campaign during the American Revolutionary War, lasting from June to October 1779, against the four British-allied nations of the Iroquois. The campaign was ordered by George Washington in response to the 1778 Iroquois and British attacks on the Wyoming Valley, German Flatts, and Cherry Valley. The campaign had the aim of "taking the war home to the enemy to break their morale." The Continental Army carried out a scorched-earth campaign in the territory of the Iroquois Confederacy in what is now western and central New York.