The whole country around New Orleans, and indeed the entire region adjacent to the Mississippi and its bayous, would be overflowed in times of freshet were it not for the elaborate systems of levees, which are a special feature of the whole lower Mississippi Valley. The work of constructing these extensive embankments began at the foundation of the infant city of New Orleans, when a dyke a mile long was projected to protect the settlement from overflow, and it was built soon afterwards. In 1770 the settlements extended thirty miles above and twenty miles below the city, the plantations being protected by levees. By 1828, the levees, though in many places insufficient, had become continuous nearly to the mouth of Red River. The methods of construction were various, and the authorities conflicting, but the Government took hold of the work in 1850, beginning by giving the States the swamplands to provide a fund for reclamation. When the Civil War began, the levees extended a thousand miles along the river, and as far north as the State of Missouri. During the war the system fell into decay, and afterwards much work of restoration was necessary. The Mississippi River Commission now has charge, under comprehensive methods, and large sums are devoted to the purpose, aggregating over $4,000,000 annually from the General Government and the States, there being continuous lines of levees from Memphis nearly to the delta below New Orleans. Were the river left to itself, in most of this region during the spring floods it would overflow the banks by several feet, this being, however, prevented by these massive earth entrenchments, through which there nevertheless often breaks a destructive crevasse. The sediment brought down by the river has been deposited most abundantly upon the banks, making their front the highest surface, so that there is a gradual descent inland and back from the river of about four feet to the mile. During the floods, an observer standing alongside the levee has the water in the river running high above him, and when the levee breaks the bottom-lands are soon extensively overflowed. The estimate is that these lands, reclaimed and protected by the levees, embrace thirty thousand square miles of the most fertile soil in the world, about one-sixth of it being under cultivation; and that there are altogether twenty-six hundred miles of levees along the great river, and the adjunct tributary bayous, lakes and other water-courses. For nine months the water stage is low, so that very little attention is given it, but when the spring comes, the melted snows of the Rockies and the torrential rains come down usually in conjunction, bringing an enormous flood, that rushes along, filling the river to the tops of the embankments. Processes of decay and weakening are always going on--rats and mice have their burrows, and millions of crawfish, with claws like chisels, riddle the levees with holes. Then in some