The Sullivan Expedition, also known as the Sullivan-Clinton Expedition, led by Major General John Sullivan and Brigadier General James Clinton was an extended systematic military campaign against Loyalists (""Tories"") and the four Amerindian nations of the Iroquois who had sided with the British in the American Revolutionary War. It occurred mainly in the lands of the Iroquois Confederacy, which is today the heartland of New York State.The expedition occurred during the summer of 1779, beginning June 18 when the army marched from Easton, Pennsylvania, to October 3 when it abandoned Fort Sullivan, built at Tioga, to return to George Washington's main camp in New Jersey. While the campaign only had one major battle, at Newtown (since the tribes evacuated ahead of the large military force) along the Chemung River in western New York, the expedition severely damaged the Iroquois nations' economies by burning their crops, villages, and chattels, thus ruining the Iroquois technological infrastructure . With the Amerindians' shelter gone and food supplies destroyed, thereafter the strength of the Iroquois Confederacy was broken. The death toll from exposure and starvation dwarfed the casualties received in the Battle of Newtown, in which about 1,000 Iroquois and Loyalists were decisively defeated by an army of 3,200 Continental soldiers. Sullivan's army carried out a scorched earth campaign, methodically destroying at least forty Iroquois villages throughout the Finger Lakes region of western New York, to put an end to Iroquois and Loyalist attacks against American settlements as had occurred the previous year of 1778 such as the Cobleskill, Wyoming Valley and Cherry Valley massacres. The survivors fled to British regions in Canada and the Niagara Falls and Buffalo areas. The devastation created great hardships for the thousands of Iroquois refugees who fled the region to shelter under British military protection outside Fort Niagara that winter, and many starved or froze to death, despite attempts by the overstressed resources of the British authorities to import food and provide shelter.The Sullivan Expedition devastated the Iroquois crops and towns and left them dependent upon the mercy of the British for the harsh winter of 1779.