Frederick Jackson Turner's groundbreaking and controversial essay is based on his definitive thesis, "The existence of an area of free land, its continuous recession, and the advance of American settlement westward, explain American development." ( Turner, p. 27) An introduction by Harold Simonson analyzes and describes the author and his influential essay in historical perspective. Turner was born in 1861, one year before passage of the Homestead Act. His parents had left upper New York State to settle in a small frontier town in Portage, ....