in the United States
was the zone of unsettled land to the west of the existing settlements. As settlement occurred the frontier moved west and by about 1890
ceased to exist when the remaining large patches of unsettled land in the interior of the country between the east and the already thickly settled Pacific
coast were filled in. The frontier by official definition of the census
was a line west of which the population was less than 2 persons per section (one square mile
). The frontier was very productive of both adventures and stories. Western movies
are generally set on the frontier.
See Wild West, trans-Appalachia.