In reality, no one single-handedly creates a new field of historical inquiry. As soon as you open your mouth to pronounce George Grote the modern father of ancient Greek history, you remember that August Boeckh, Karl Otfried Müller, and Connop Thirlwall laid Grote's groundwork. But it almost seems as if Michael O'Brien has pulled off such a feat. Taking the scattered bricks of the intellectual history of the antebellum American South, he has, over long years of labor, built from them a coherent structure where none existed before, a many-roomed mansion of the mind. The two volumes and 1,200 pages of Conjectures of Order: Intellectual Life and the American South, 1810–1860 culminate a quarter-century of rare scholarly achievement.