Turner 's ideas since 1893 have inspired Influence generations of historians ( and critics ) to explore Scrutiny multiple individual American frontiers , but the popular folk frontier concentrates on the conquest Conquering and settlement Statement of Native American lands west of the Mississippi River , in what is now the Midwest , Texas , the Great Plains , the Rocky Mountains , the Southwest , the West Coast , and Hawaii .

Altogether , more than 200 million people were affected Influence , in an area ranging Cause_change_of_position_on_a_scale from the Rocky Mountains to the Atlantic Ocean and extending Expansion south to include Cause_to_be_included roughly 187 million residents of the Continental United States .