Encyclopædia Britannica, Ninth Edition/Mississippi (2.)

MISSISSIPPI, one of the Southern States of the American Union, derives its name from the river which for more than 500 miles forms its western boundary between the 35th and 31st parallels of north latitude, separating it from Arkansas and Louisiana. The boundary with the latter State is continued along the 31st parallel, for 110 miles, to the Pearl river, and then down the Pearl to its mouth. The Gulf of Mexico, eastward from the mouth of Pearl river, completes the southern boundary. On the north the 35th parallel, from the Mississippi river to the Tennessee, separates the State from Tennessee, and the boundary then follows the latter river to the mouth of Bear Creek, in 34° 53' N. lat. and 88° 15' W. long. The eastern boundary of the State, separating it from Alabama, follows a line drawn from the mouth of Bear Creek about seven degrees west of south to what was

&ldquo;the north-western corner of Washington county on the Tombigbee,&rdquo; and thence due south to the Gulf of Mexico. Ship, Horn, Cat, and Petit Bois Islands, and those nearer the shore, form a part of Mississippi. The extreme length of the State, north and south, is 330 miles, and its maximum breadth is 188 miles. Under the United States surveys, begun in 1803, the State has been divided into townships and sections, except such parts as were at the first owned by individuals. The area of the State is given in the census reports for 1880 as 46,340 square miles.

Topography.&mdash;There are no mountains in Mississippi, but a considerable difference of level exists between the continuously low, flat, alluvial region lying along and between the Mississippi and Yazoo rivers, called &ldquo;the Bottom,&rdquo; and nearly all the remainder of the State, which is classed as upland. The latter part, comprising five-sixths of the whole, is an undulating plateau whose general elevation above the water of the Gulf of Mexico increases to 150 feet within a few miles of the coast, and varies elsewhere from 150 to 500 or 600 feet. Some exceptional ridges are probably 800 feet high. The streams of this region flow in valleys varying in width from a few hundred yards to several miles. The fall of each river is not great, and is quite uniform. Usually a considerable part of the valley of each larger stream is several feet above its present high water mark, and forms the &ldquo;hommock,&rdquo; or &ldquo;second bottom&rdquo; lands. On some of the rivers the lowest part of the valley, subject to overflow, is several miles in width, and bears a resemblance to the Mississippi Bottom.

Ridges or plateaus everywhere in the upland region divide the contiguous basins of creeks and rivers, descending more or less abruptly to their valleys. In the north-eastern part of the State, almost level prairies cover large areas overlying a Cretaceous formation called Rotten Limestone.

A line of abrupt bluffs, extending southward from the north-west corner of the State, divides the upland region from the Bottom, where the general surface lies below the high-water level of the Mississippi river. A few low ridges, running north and south, and embracing about 200,000 acres, are barely above high water. The cultivated lands in the Bottom lie on these, and on the borders of the rivers and the numerous lakes and bayous, where the surface is slightly elevated. Low swamps or marshes, in which flourish large cypress trees (Taxodium distichum), lie between the streams, and frequently receive the surface drainage from their banks. Large forest trees and dense cane-brakes (Arundinaria gigantea) occupy the drier ground. The Mississippi river is prevented from flooding the Bottom during high water by a system of levees or embankments built by a fund derived partly from taxation on the land and partly from the proceeds of the sale of public lands in the State classed as &ldquo;swamp lands,&rdquo; which were given over for this purpose by Congress. The only compensation for the injury done when breaks in the levees (&ldquo;crevasses&rdquo;) occur is the deposit of alluvial matter left by the overflow, which adds to the productiveness of the already wonderfully fertile soil. The present levee system usually protects about one-fourth of the 4,000,000 acres in the Bottom. Many crescent-shaped lakes (&ldquo;cut-offs&rdquo;) occur in the Bottom. Similar phenomena present themselves in the channels of the other rivers having wide bottoms.

The volume of water in the streams varies greatly during the year, and is usually largest between the months of January and April. During high water all the larger streams are navigable by steamboats. These ply upon the Mississippi, Tennessee, and Yazoo rivers throughout the whole year. The rivers flowing into the Gulf are much obstructed by sand-bars, and are chiefly used for floating logs to the saw-mills on the coast.

The best and only deep harbour on the coast is the well-protected roadstead inside of Ship Island. It has a depth of 27 feet, a firm clay bottom, and is readily accessible to lighters from the shallower harbours along the coast.



Geological Map of Mississippi State.