The valley of the Mississippi river and its tributaries, (this stream and its adjuncts involve a big part of the question,) comprehends more than twelve hundred thousand square miles, the greater part prairies. It is by far the most important stream on the globe, and would seem to have been marked out by design, slow-flowing from north to south, through a dozen climates, all fitted for man's healthy occupancy, its outlet unfrozen all the year, and its line forming a safe, cheap continental avenue for commerce and passage from the north temperate to the torrid zone. Not even the mighty Amazon (though larger in volume) on its line of east and west--not the Nile in Africa, nor the Danube in Europe, nor the three great rivers of China, compare with it. Only the Mediterranean sea has play'd some such part in history, and all through the past, as the Mississippi is destined to play in the future. By its demesnes, water'd and welded by its branches, the Missouri, the Ohio, the Arkansas, the Red, the Yazoo, the St. Francis and others, it already compacts twenty-five millions of people, not merely the most peaceful and money-making, but the most restless and warlike on earth. Its valley, or reach, is rapidly concentrating the political power of the American Union. One almost thinks it _is_ the Union--or soon will be. Take it out, with its radiations, and what would be left? From the car windows through Indiana, Illinois, Missouri, or stopping some days along the Topeka and Santa Fe road, in southern Kansas, and indeed wherever I went, hundreds and thousands of miles through this region, my eyes feasted on primitive and rich meadows, some of them partially inhabited, but far, immensely far more untouch'd, unbroken--and much of it more lovely and fertile in its unplough'd innocence than the fair and valuable fields of New York's, Pennsylvania's, Maryland's or Virginia's richest farms. PRAIRIE ANALOGIES--THE TREE QUESTION The word Prairie is French, and means literally meadow. The cosmical analogies of our North American plains are the Steppes of Asia, the Pampas and Llanos of South America, and perhaps the Saharas of Africa. Some think the plains have been originally lake-beds; others attribute the absence of forests to the fires that almost annually sweep over them--(the cause, in vulgar estimation, of Indian summer.) The tree question will soon become a grave one. Although the Atlantic slope, the Rocky mountain region, and the southern portion of the Mississippi valley, are well wooded, there are here stretches of hundreds and thousands of miles where either not a tree grows, or often useless destruction has prevail'd; and the matter of the cultivation and spread of forests may well be press'd upon thinkers who look to the coming generations of the prairie States. MISSISSIPPI VALLEY LITERATURE