The American destruction of the Six Nations' homelands came as a result of the destructive raids carried out by the Indians and American loyalists on the frontiers of New York and Pennsylvania in 1778. The raids crippled the American Continental Army by depriving it of food and manpower, and spread terror by destroying frontier settlements and taking prisoners. This forced the settlements to be abandoned for a time, if not indefinitely. By 1779, New York Governor George Clinton was reporting that the frontier of New York would be pushed back to the Hudson River if these raids were allowed to continue.
In response to this situation, General Washington decided to commit a better part of the Continental Army to destroying the ability of the Six Nations to wage war on the Americans. The goal of the expedition would be to completely destroy the principal villages and food supplies of the Cayuga and Seneca Indian Nations. At the very best, it was hoped this expedition would force the Six Nations to sue for peace with the Americans. At the very least, it was hoped that the Six Nation's ability to remain on the attack would be permanently crippled. A further goal of the expedition was to take a large number of Indians prisoners, to be held as hostages to help ensure the "good behavior" of the Indians in the future. In effect, the Americans would employ the Indians own tactics against them.
Command of the expedition was given to General John Sullivan, with General James Clinton serving as his second in command. The fact that four brigades of Continental troops totaling around 4,469 men were earmarked for this expedition underlines just how important the Americans felt this enterprise was. This force of regulars was made up of troops from New York, New Jersey, New Hampshire, and Pennsylvania, and was augmented by smaller groups of riflemen, militia, and Oneida Indians. In addition to this main operation, two smaller expeditions would destroy Seneca settlements in western Pennsylvania and Onondaga settlements in central New York.
It was decided to invade the Six Nations by moving north up the Susquehanna River from Pennsylvania. The New York Brigade under Clinton was to assemble at Canajoharie on the Mohawk River. Clinton's force would then move southwest through New York, destroying whatever Indian villages were in its path. Upon linking up with Gen. Sullivan at Tioga (on the Pennsylvania-New York border), the combined force would move into the heart of Six Nations' land. The expedition was supposed to begin in May, but was held up due to a lack of supplies and the need to construct military roads through the wilderness areas. This delay would end up working to the Americans' advantage as it helped to convince the British that the Americans were not planning any significant actions against the Six Nations.
British distrust of their allies worked in the Americans' favor as well. The British refused to believe that the Americans could mass as large a force as the Indians reported was gathering near the borders of Pennsylvania and New York. Even after White scouts confirmed the Indian's reports the British were still skeptical. American diversionary movements convinced the British that the Americans planned to attack Fort Detroit to attempt another invasion of Canada. The British never conceived that the Americans would attempt an invasion of the Six Nation's homeland. By the time the British realized the Americans' true intent it was far too late to assist the Indians in any way.
By the beginning of August, Sullivan's forces had arrived at Tioga, where they had begun the campaign by destroying the nearby mixed Indian/white settlement of Chemung. The troops arrived on August 22, and on August 26, the American forces began their invasion. To counter this invasion, the British could muster only around 600 British, loyalists, and Indians. Reinforcements in the form of Sir John Johnson's King's Royal Regiment of New York and additional Indians were eventually sent out, but by the time they left Canada, the American force had come and gone.
The commander of the British force, loyalist Colonel John Butler, advocated a strategy of guerilla tactics, retreating in the face of the larger American force while sending out small parties to continually harass and alarm the Americans. A small party of Delaware Indians however, who also had villages nearby, would not agree to this strategy. They wished to stand and fight before the Americans could cause anymore damage. To preserve the Indian's unity, many Six Nations War Chiefs, against their better judgment, agreed. Butler had no choice but to comply with the Indians' decision. For once, the Indians were going to abandon their most effective tactics in favor of a standing battle, with more disastrous results.
The Indians chose a ridge overlooking the route of Sullivan's advance, at a point where the path narrowed to a small passage near the Indian village of Newtown. They built concealed breastworks so that they could ambush the American force at the start of the battle. There the mixed loyalist, Indian, and British force waited for the American approach.
On the afternoon of August 29, Sullivan's troops approached the ambush site. Unfortunately for the Indians, the Americans knew a large body of the enemy was nearby and they were being particularly cautious and vigilant. Their advance parties spotted the hidden breastworks and sent back word to the main force. Sullivan determined to occupy the Indians in front of their breastworks with a mixed force of infantry and artillery, while the New Hampshire and New York troops encircled the ridge. Col. Butler surmised the Americans' plans early on, and once again urged the Indians to retreat, but they steadfastly refused to budge.
The Indians' resolve was soon shaken as artillery rounds began to fall around them. As the American attack intensified, the Indians and their British allies were forced to retreat from their positions. Mortar shells bursting in the rear of their lines convinced many Indians that they were already encircled, and panic began to spread through their numbers. Luckily for the Indians, the Americans' flanking column had been slowed down in crossing a creek and a swamp. Thus, the main body of the Indians and their allies were able to escape just ahead of the noose that was tightening around them. With their retreat, the Battle of Newtown came to an end.
While the Americans did inflict a considerable amount of casualties amongst the Indian forces, their true victory was in totally over powering the Indians and completely destroying their morale. For the remainder of the campaign, the Americans would be unhindered in their destructive advance.
Morale in the American Army was high after the battle. They even agreed to subsist on half rations supplemented by produce from the villages they encountered for the remainder of the campaign. By September 1, Sullivan's force had reached Seneca Lake and proceeded to destroy all the principal villages in the area. Many of the troops were shocked upon entering these villages. They found not the crude bark huts or longhouses of "Savages," but instead orderly rows of houses built of hewn timbers and frame houses with windows. Well-cultivated vegetable fields extended out from the villages, along with extensive apple, peach, and cherry orchards. Many of these Indian villages rivaled or surpassed the towns that the soldiers had come from.
Col. Butler attempted to rally the Indians to defend Kanadesaga, one of the chief Seneca towns and base for Butler's loyalist troops. The Indians were still thoroughly intimidated from the encounter at Newtown however, and thought only of removing their families to safety. By September 9, Sullivan's force had destroyed all the major settlements in the area of Canandaigua Lake. They now halted while Sullivan sent out a scouting party towards Chenussio, one of the largest Seneca towns, which sat alone the Genesee River. This party, 26 men under Lieutenant Thomas Boyd, would become the only battle casualties that the Americans suffered.
Col. Butler had finally convinced the Indians to attempt one last stand against the invasion of their homeland. A force of 400 Indians and white troops lay in ambush for the Americans as they constructed a bridge across a swampy area. Boyd's party, returning from their scouting mission, inadvertently stumbled into this ambush. Thinking they had been discovered, the main body of Indians surged forward and destroyed Boyd's party. Only a few Americans escaped to return to Sullivan's army. Lt. Boyd and another soldier we captured, as well as Hanyost Thaosagwat, an Oneida scout. Thaosagwat was immediately killed and mutilated by the infuriated Senecas. After being questioned by Col. Butler, Boyd and the other soldier were on their way to Fort Niagara, under loyalist guard, when they were wrested away by Indians at Chenussio. All the Indians' frustration over their situation was now poured out on Boyd and his fellow captive, who were both horribly tortured and mutilated before they were both finally killed. With the failure of the ambush in the swamp, the Indians made no further attempts to halt the American advance and continue their westward retreat.
On September 14, Sullivan's army reached Chenussio, and destroyed 128 houses and the extensive fields of fruits and vegetables. Under the mistaken impression that there were no other significant Seneca towns west of the Genesee River, the American force now turned around and began their homeward march, destroying any villages they had missed during their advance. By September 21, there were 5,036 Indians at Fort Niagara, expecting assistance from the British. Famine at the garrison was narrowly avoided by the arrival of additional supplies and by convincing many of the Indians to form temporary settlements elsewhere.
By the end of the expedition, Sullivan's army had destroyed over forty villages and many isolated homes. They had destroyed at least 160,000 bushels of corn, and an untold number of other vegetables and fruit, with the loss of only 40 men. Noticeably missing however, was the presence of any Indian captives, one of the main goals of expedition.
This seeming victory proved to be hollow in other respects as well. A large number of Indians that may have kept a neutral stance in the war were now by necessity and a thirst for revenge, pushed to the side of the British. While the Indian raids were temporarily blunted, the Indians would return in 1780 and thereafter to launch even larger and more destructive raids against American settlements.
Perhaps the major victory obtained by the Americans was destroying yet another aspect of the Six Nations Indians ability to be independent and take care of themselves. For the remainder of the war, the Indians would be almost wholly dependent upon the British for food, clothing, and equipment. This also strained British resources, and in the end, the British would abandon their Indian allies. The British made no provisions for the Indians in their Peace treaty with the Americans in 1783. This left the Six Nations still defiant but ill-prepared to deal with the new United States.