The area of Pompey was originally part of the territory traditionally occupied by the historic Onondaga, one of the Five Nations of the Iroquois tribes of the powerful "Haudenosaunee", or Iroquois Confederacy. After the American Revolutionary War, when most of the Iroquois were forced to cede their land to the victorious United States, many of the Onondaga migrated to Canada. The British Crown awarded them land there for resettlement for their support during the war. New York State took over the former Iroquois lands and sold much of the public land for development (and speculation). It reserved part as the Central New York Military Tract. Veterans of the Revolution were awarded land grants in this tract as payments for service. The town was first settled by outsiders around 1789, as Yankees from New England and other migrants moved into western New York.