INTRODUCTION                        dxxi
to usher in a generation of strife; but for forty years the failure of English colonial policy in the Northwest, the American Revolution, the separatist plots and disorders of the Critical Period successively bore their testimony to the equilibrium disturbed in the Peace of 1763.
Not till the Louisiana Purchase of 1803 once more reunited the valley, did political quiet return in the wake of political order and economic unity, or the essential oneness of the Great Valley establish itself to decree the doom of the Southern Confederacy, under a leader born and bred amid the tributaries of the Mississippi, who in his youth had witnessed the inevitable gathering of its waters by "the Island on which New Orleans is situated."