George Bancroft, History of the United States from the Discovery of the American Continent, Vol. 10

The Mississippi river is the guardian and the pledge of the union of the states of America. Had they been confined to the eastern slope of the Alleghanies, there would have been no geographical unity between them, and the thread of connection between lands that merely fringed the Atlantic must soon have been sundered. The father of rivers gathers his waters from all the clouds that break between the Alleghanies and the furthest ranges of the Rocky mountains. The ridges of the eastern chain bow their heads at the north and at the south; so that long before science became the companion of man, nature herself pointed out to the barbarous races how short portages join his tributary rivers to those of the Atlantic coast. At the other side, his mightiest arm interlocks with the arms of the Oregon and the Colorado, and by the conformation of the earth itself marshals highways to the Pacific. From his remotest springs he refuses to suffer his waters to be divided; but, as he bears them all to the bosom of the ocean, the myriads of flags that wave above his head are all the ensigns of one people. States larger than kingdoms flourish where he passes; and, beneath his step, cities start into being, more marvellous in their reality than the fabled creations of enchantment. His magnificent valley, lying in the best part of the temperate zone, salubrious and wonderfully fertile, is the chosen muster-ground of the most various elements of human culture brought together by men, summoned from all the civilized nations of the earth, and joined in the bonds of common citizenship by the strong, invisible