The 1760 Treaty of Oswegatchie was signed during the Seven Years’ War and assured neutrality between the Seven Nations (former Indigenous allies of the French) and the British. (See also Treaties with Indigenous Peoples in Canada.)
During the Seven Years’ War, the commander-in-chief of the British forces, General Jeffrey Amherst, issued a proclamation on 26 April 1760 designed to win over France’s allies. The proclamation Amherst delivered told Indigenous peoples that "His Majesty has not sent me to deprive any of you of your Lands or Property." Amherst promised that in return for their support they would be maintained in their "just rights," including their hunting territories. (See also Indigenous Territory.)
When the British invasion force reached Fort Lévis and the réduction (reserve) of La Présentation in mid-August, Sir William Johnson, superintendent of Indian Affairs, met with Indigenous delegates to draw up a treaty of neutrality.
Sir William Johnson solemnly promised to the Seven Nations — consisting of Oswegatchie (La Presentation), Akwesasne, Kanesatake, Kahnawake, Odanak, Becancour (Wolinak), and Lorette — to secure the possession of their lands and the free exercise of the Catholic religion. France's former allies promised to remain neutral during the remainder of the war in return for a promise not to be treated thereafter as enemies.
The terms of the agreement were confirmed at a special meeting on 15-16 September 1760 at Kahnawake and reconfirmed on 21 August 1769. In a letter to the British prime minister, Johnson said that the Seven Nations had "ratified a treaty with us."