For other people of this same name, see Frederick Jackson (disambiguation) and Frederick Turner (disambiguation).Frederick Jackson Turner (November 14, 1861 – March 14, 1932) was an American historian in the early 20th century, based at the University of Wisconsin until 1910, and then at Harvard. He was primarily known for his “Frontier Thesis.” He trained many PhDs who came to occupy prominent places in the history profession. He promoted interdisciplinary and quantitative methods, often with a focus on the Midwest. He is best known for his essay "The Significance of the Frontier in American History", whose ideas formed the Frontier Thesis. He argued that the moving western frontier shaped American democracy and the American character from the colonial era until 1890. He is also known for his theories of geographical sectionalism. In recent years historians and academics have argued strenuously over Turner's work; all agree that the Frontier Thesis has had an enormous impact on historical scholarship and the American soul.