During the American Revolution, the British base at Fort Niagara served as a safe haven for those loyal to the British, whether European settlers or Haudenosaunee villagers, and a base for offensive operations against colonial settlements on the frontier.
Combined colonial and Native American forces organized at Fort Niagara conducted raids against colonial settlements in the Mohawk Valley and northeastern Pennsylvania, their former neighbors, in an escalating cycle of violence and atrocities.
Active participation by most Haudenosaunee tribes on the British side and some on the American side through raids on the frontier led to the targeting of their villages in central New York by American forces. As a result of the war, the Six Nations were divided, with some moving to Ontario and others staying in New York; the Tuscarora fought on both sides of the Revolutionary War. Post-war treaties shrank Haudenosaunee lands to a few scattered reservations, opening Western New York for settlement by Europeans.
On October 13, 1812, the United States invaded Canada. Lewiston was the staging area for the Battle of Queenston Heights, the first major battle of the War of 1812. Cannons installed on the lawn of Barton Hill were aimed at the village of Queenston, across the Niagara River in Canada. Troops were quartered on Major Barton's property as well.