free land, its continuous recession, and the advance of American settlement westward, explain American development." Through treaties with foreign nations and native tribes, political compromise, military conquest, the establishment of law and order, the building of farms, ranches, and towns, the marking of trails and digging of mines, and the pulling in of great migrations of foreigners, the United States expanded from coast to coast, fulfilling the ideology of Manifest destiny. In his "Frontier Thesis" (1893), Turner theorized that the frontier was a process that transformed Europeans into a new people, the Americans, whose values focused on equality, democracy, and optimism, as well as individualism, self-reliance, and even violence.