Frontier Thesis

The Frontier Thesis or Turner Thesis, is the argument advanced by historian Frederick Jackson Turner in 1893 that the origin of the distinctive egalitarian, democratic, aggressive, and innovative features of the American character has been the American frontier experience. He stressed the process—the moving frontier line—and the impact it had on pioneers going through the process. In the thesis, the frontier established liberty by releasing Americans from European mind-sets and ending prior customs of the 19th century. Turner first announced his thesis in a paper entitled "The Significance of the Frontier in American History", delivered to the American Historical Association in 1893 in Chicago. Turner elaborated on the theme in his advanced history lectures and in a series of essays published over the next 25 years, published along with his initial paper as The Frontier in American History.

Other historians had begun to explore the meaning of the frontier, such as Theodore Roosevelt, who had a different theory. Roosevelt argued that the battles between the trans-Appalachian pioneers and the Indians in the "Winning of the West" had forged a new people, the American race. His emphasis on the importance of the frontier in shaping American character influenced the interpretation found in thousands of scholarly histories. His model of sectionalism as a composite of social forces, such as ethnicity and land ownership, gave historians the tools to use social history as the foundation for all social, economic and political developments in American history. By the time Turner died in 1932, 60% of the leading history departments in the U.S. were teaching courses in frontier history along Turnerian lines.