The American frontier was generally the westernmost edge of a settlement and typically more free-spirited than in the East because of its lack of social and political institutions. The idea that the frontier provided the core defining quality of the United States was elaborated by the historian Frederick Jackson Turner , who built his Frontier Thesis in 1893 around this notion. Subsequently, the frontier has also been described as the point of contact between two cultures, where contact led to exchanges that affected both cultures. 
We may examine representative incidents by following the geographic route of European settlement, beginning in the New England colonies. There, at first, the Puritans did not regard the Indians they encountered as natural enemies, but rather as potential friends and converts. But their Christianizing efforts showed little success, and their experience with the natives gradually yielded a more hostile view. The Pequot tribe in particular, with its reputation for cruelty and ruthlessness, was feared not only by the colonists but by most other Indians in New England. In the warfare that eventually ensued, caused in part by intertribal rivalries, the Narragansett Indians became actively engaged on the Puritan side.