Martin Ridge was a Senior Research Associate at the Henry E. Huntington Library, San Marino, California — a position first held by Frederick Jackson Turner. He died in 2003.
Frederick Jackson Turner was an American historian based at the University of Wisconsin, and later Harvard University, in the early 20th Century who is most remembered for his "Frontier Thesis," which drew from his essays on the American frontier like "The Significance of the Frontier in American History." In his thesis, Turner argued that the moving western frontier shaped American democracy and the American character. Turner died in 1932 but his "Frontier Thesis" is still studied today.