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MISSISSIPPI
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MISSISSIPPI b See also:RIVER, the central artery of the river See also:system which drains the greater See also:part of the See also:United States of See also:America lying between the Appalachian Mountains on the See also:east and the Rocky Mountains on the See also:west. It rises in the See also:basin of Itasca See also:Lake, in See also:northern See also:Minnesota, and flows mostly in a southerly direction to the Gulf of See also:Mexico. In the region of its headwaters are numerous lakes which were formed by glacial See also:action, but the river itself was old before the glacial See also:period, as is shown by the crumbling rocks on the edges of the broad and driftless valley through which it flows along the S.E. border of Minnesota and the S.W. border of See also:Wisconsin, in contrast with the precipitous bluffs of hard See also:rock on the edges of a valley that is narrow and steep-sided farther down where the river was turned from its See also:ancient course by the See also:glacier. So See also:long as the outlet of the See also:Great Lakes through the St See also:Lawrence Valley was blocked by the icy See also:mass, they were much larger than now and discharged through the See also:Wabash, See also:Illinois and other See also:rivers into the Mississippi. Below the glaciated region, that is from See also:southern Illinois to the Gulf, the river had carved before the See also:close of the glacial period a See also:flood-See also:plain varying in width from 5 to 8o m., but this has been filled to a See also:depth of roo ft. or more with See also:alluvium, and in the See also:post-glacial period an inner valley has been formed within the See also:outer one. The See also:total length of the river proper from the source near
Lake Itasca to its mouth in the Gulf of Mexico is 2553 m.; but the true source of the river is at the See also:fountain-See also:head of the
See also:Missouri, in the Rocky Mountains, on the S.W. border of Mon See also:tana, 8000 ft. above the See also:sea, and from this source there is a continuous stream to the Gulf which is 4221 M. long—the longest in the See also:world. The Mississippi and its tributaries have more than 15,000 M. of navigable waterways and drain an See also:area of approximately 1,250,000 sq. m. The system extends through the See also:heart of the See also:continent and affords a See also:direct See also:line of communication between temperate and tropical regions. Certain See also:physical and hydrographic features, however, make the regulation and
' Removed from See also:office by Federal troops, 2znd of May 1865; W. L. Sharkey was appointed provisional See also:governor by See also:President
See also: ' Resigned 29th of See also: As the channel distance between these bends may be many See also:miles, a cascade perhaps 5 or 6 ft. in height is formed, and the torrent rushes through with a roar audible for miles. The checking of the current at the upper and lower mouths of the abandoned channel soon obstructs them by See also:deposit, and forms in a few years one of the See also:crescent lakes which are so marked a feature on the maps. At the mouth of the Red river, 316 m. above the passes, the water See also:surface at the lowest See also:stage is only 5i ft. above the level of the Gulf, where the mean tidal oscillation is about i i ft. The river channel in this See also:section is therefore a fresh-water lake. At the flood stage the surface rises 5o ft. at the mouth of Red river, but of course retains its level at the Gulf, thus giving the head necessary to force forward the increased See also:volume of discharge. Above the mouth of the Red river the See also:case is essentially different. The width increases and the depth decreases. Hence the general slope in long distances is here nearly the same at all stages. The effect of these different physical conditions appears in the See also:comparative volumes which pass through the channel. At New See also: It begins to rise again in See also:February, as a consequence of the storms from the Gulf which See also:traverse the basin of the Ohio, and attains its highest point about the 1st of See also:April. It then falls a few feet, but the rains in the Upper Mississippi basin cause it to rise again and high water is maintained until some See also:time in June by the See also:late See also:spring and See also:early summer rains in the Missouri basin. As a See also:rule the river is above See also:mid-stage from See also:January to See also:August inclusive, and below that level for the See also:remainder of the See also:year. See also:Engineering See also:Works.—Below Cape Girardeau there are at least 29,790 sq. m. of See also:rich bottom lands which require See also:protection from floods, and this has been accomplished to a great extent by the erection of levees. The first See also:levee was begun in 1717, when the engineer, Le Blond de La Tour (d. about 1725) erected one a mile long to protect the See also:infant See also:city of New Orleans from over-flow. Progress at first was slow. In 1770 the settlements extended only 3o m. above and zo m. below New Orleans; but in 1828 the levees, although quite insufficient in dimensions, had become continuous nearly to the mouth of the Red river. In 185o a great impulse was given to systematic See also:embankment by the United States See also:government, which turned over to the several states all unsold swamps and overflowed lands within their limits, to provide a fund for reclaiming the districts liable to inundation. The action resulting from this caused alarm in See also:Louisiana. The aid of the government was invoked, and See also:Congress immediately ordered the necessary investigations and surveys. This See also:work was placed in See also:charge of See also:Captain (later General) See also:Andrew A. See also:Humphreys (1810—1883), and an elaborate See also:report covering the results of ten years of investigation was published, just after the outbreak of the See also:Civil See also:War in 1861. In this report it was demonstrated that the great bottom lands above the Red river before the construction of their levees did not, as had been supposed, in Louisiana, serve as reservoirs to diminish the maximum See also:wave in great flood seasons. Further-more, the report argued that no diversion of tributaries was possible; that no reservoirs artificially constructed could keep back the spring freshets which caused the floods; that the making of cut-offs, which had sometimes been advocated as a measure of See also:relief, was in the highest degree injurious; that outlets were impracticable from the lack of suitable sites; and, finally, that levees properly constructed and judiciously placed would afford protection to the entire alluvial region. During the Civil War (1861—65) the artificial embankments were neglected; but after its close large sums were expended by the states directly interested in repairing them. The work was done without See also:concert upon defective plans, and a great flood early in 1874 inundated the See also:country, causing terrible suffering and loss. Congress, then in session, passed an See also:act creating a See also:commission of five See also:engineers to determine and report on the best system for the permanent reclamation of the entire alluvial region. Their report, rendered in 1875, endorsed the conclusions of that of 1861, and advocated a general levee system on each See also:bank. This system comprised: (I) a See also:main embankment raised to specified heights sufficient to restrain the floods; and (2) where reasonable See also:security against caving required considerable areas near the river to be thrown out, exterior levees of such a height as to exclude See also:ordinary high waters, but to allow See also:free passage to great floods, which as a rule occur only at intervals of five or six years. An engineering organization was proposed for constructing and maintaining these levees, and a detailed topographical survey was recommended to deter-mine their precise location. Congress promptly approved and ordered the survey; but strong opposition on constitutional grounds was raised to the construction of the levees by the government. In the meantime complaints began to be heard respecting the See also:low-water See also:navigation of the river below the mouth of the Ohio. A See also:board of five See also:army engineers, appointed in 1878 to consider a See also:plan of relief, reported that a depth of Io ft. could probably be secured by narrowing the wide places to about 3500 ft. with See also:hurdle work, See also:brush See also:ropes or brush dykes designed to cause a deposit of sediment, and by protecting caving banks by See also:light and cheap mattresses. Experiments in these methods were soon begun and they proved to be effective. The bars at the efflux of the passes at the mouth of the Mississippi were also serious impediments to See also:commerce. The river naturally discharges through three See also:principal branches, the See also:south-west pass, the south pass and the See also:north-east pass, the latter through two channels, the more northern of which is called Pass a 1'Outre. In the natural See also:condition the greatest depth did not exceed 12 or 13 ft. After appropriations by Congress in 1837, 1852 and 1856, a depth of 18 ft. was finally secured by dredging and scraping. The report of 1861 discussed the subject of See also:bar formation at length, and the stirring up of the bottom by scrapers during the flood stages of the river (six months annually) was recommended by it. After the war this recommendation was carried into effect for several years, but experience showed that not much more than 18 ft. could be steadily maintained. This depth soon became insufficient, and in 1873 the subject was discussed by a board of army engineers, the See also:majority approving a See also:ship See also:canal. In 1874 Congress constituted a See also:special board which, after visiting See also:Europe and examining similar works of improvement there, reported in favour of constructing jetties at the south pass, substantially upon the plan used by Pieter Caland (b. 1826) at the mouth of the See also:Meuse; and in 1875 Captain See also: The required 'iepth was obtained in 1879, and with few interruptions has beenmaintained. In 1902 Congress authorized preparations for the construction of a deeper (35 ft.) and a wider channel through the south-west pass; the work was begun in 1903 and virtually completed in 1909.
In the year in which Captain Eads opened the south pass of deep-water navigation Congress created a commission of seven members to mature plans for correcting and deepening the channel of the river, for protecting its banks and for preventing floods, and since then large expenditures for improvement between the head of the passes and the mouth of the Ohio have been under the control of this commission. In protecting the banks, mattresses of brush or small trees, See also:woven like See also:basket-work, were sunk on the portion of the bank at the time under water, by throwing See also:rubble See also: Navigation interests demanded more speedy relief. The commission then began experimenting with See also:hydraulic dredges, and in 1896 it adopted a project for maintaining a channel from the mouth of the Ohio to the passes that should be at least 9 ft. deep and 250 ft. wide throughout the year. Centrifugal pumps are used, the suction pipes being at the See also:bow and the discharge at the stern through a line of pipes about moo ft. long, supported on pontoons. Water jets or cutters stir up the material to be dredged before it enters the suction pipes. The later dredges have a capacity of about woo cub. yds. of See also:sand per See also:hour, the velocity in the 32- to 34-in. discharge pipes being from to to 15 ft. per second. They cost from $86,000 to $120,000, and. their working during a low-water See also:season See also:costs about $20,000. These dredges begin work on a bar where trouble is feared before the river reaches its lowest stage, and make a cut through it. A common cut is 2000 ft. long by 25o ft. wide, and 3 or 4 ft. deep. Since 1903 a channel of the proposed depth or more has been maintained. In 1882 occurred one of the greatest floods known on the Mississippi, and extensive measurements of it were made. A maximum flood of 1,900,000 cub. ft. per second crossed the See also:latitude of See also:Cairo. Much of it escaped into the bottom lands, which are below the level of the great floods, and flowed through them to rejoin the river below. The flow in the river proper at Lake See also:Providence, 542 M. below Cairo, was thus reduced to about 1,000,000 cub. ft. per second, while if the river had been confined by levees the flow between them would have been See also:double, or about 2,000,000 cub. ft. per second. The volume of the levees in 1882 was about 33,000,000 cub. yds., and by the 3oth of June 1908 had been increased to 219,621,594 cub. yds., of which the United States had built about one-See also:half, and has expended on them $22,562,544. The length of the levees is about 1486 m., and they are continuous See also:save where interrupted by tributaries or by high lands, from New See also:Madrid, or 8o m. below Cairo, to Fort See also:Jackson, 1039 M. below Cairo. The width of the interval between levees on the opposite banks of the river varies greatly ; in many places the levees are built much nearer the normal margin of the river than is consistent with keeping the flood heights as low as possible. This has arisen from two causes: firstly, to give protection to lands already cultivated, which See also:lie usually near the bank of the river; secondly, to avoid the lower ground, which, owing to the See also:peculiar formation, is found as one goes back from the river. Another See also:bad result of this nearness of the levees to the bank of the river is the loss of levees by caving, which was nearly 5,000,000 cub. yds. in 1904-1905, and can only be prevented by bank protection, costing $15o,000 per mile, to protect a levee perhaps 16 ft. high costing about $30,000 per mile. The levees have See also:top widths of 8 ft., See also:side slopes of one-third, and banquettes when their heights exceed about Io ft. The grades of the levees are usually 3 ft. above the highest water, and have to be raised from year to year as greater confinement of water gives greater flood heights. When this system is completed there will probably be hundreds of miles of levee with heights exceeding 14 ft. In 1899, after about $28,000,000 had been spent on levees by the United States and by the See also:local authorities, the commission submitted an estimate for additional work on levees, amounting to 124,000,000 cub. yds. and costing $22,000,000. The effect of the levees has been to increase flood heights. Though the
Mississippi River Commission was forbidden by Congress to build the mouth of the Wisconsin to the mouth of the Arkansas in 1673.1 In 168o See also: By the war which terminated (1763) in the Treaty of See also:Paris, Great See also:Britain wrested from France all that part of the basin lying east of the middle of the river (except the See also:island of New Orleans at its mouth), together with equal rights of navigation; and the remainder of the basin France had secretly ceded to See also:Spain in 1762. During the War of See also:Independence the right to navigate the river became a troublesome question. In 1779 the See also:Continental Congress sent See also: See also:Jacob Vradenberg Brower (1844-1905), who was commissioned by the Minnesota See also:Historical Society in 1889 to make a more detailed survey, traced the source from Nicollet's Infant Mississippi to the greater ultimate See also:reservoir, which contains several lakelets, and lies beyond Lake Itasca, 2553 M. by water from the Gulf of Mexico, and 1558 ft. above the sea. Soon after this survey the See also:state of Minnesota created Itasca State See also:Park, which contains both Itasca Lake and its affluents from the south. It seems probable that See also:Joliet and See also:Marquette were preceded by two other Frenchmen, See also:Pierre Esprit Radisson and Menard Chouart See also:des Groseilliers, who apparently reached the Upper Mississippi in or about 1665; but their claim to priority has been the subject of considerable controversy, and, at all events, there was no general knowledge of the river until after the voyage of Joliet and Marquette. levees to protect lands from overflow, a majority of its members believed them useful for the purpose of navigation improvement. They have, however, effected no sensible improvement in the navigation of the river at low stages, and at other stages no improvement was needed for the purposes of navigation. Neither did they prevent a destructive flood in 1897 and again in 1903. By the 30th of June 1908, $57,510,216.81 had been appropriated for the commission's work below the mouth of the Ohio. From the mouth of the Ohio to the mouth of the Missouri, a distance of about 210 m., the river is affected by back water from the Ohio which increases the deposit of sediment, and although the banks increase in height above Cape Girardeau the channel was in its natural state frequently a mile or more in width, divided by islands, and costructed by bars on which the low-water depth was only 31 to 4 ft. The improvement was begun in 1872, and in 1881 a project was adopted for narrowing the channel to approximately 2500 ft. In 1896 dredging was begun and in 1905 the further execution of the See also:original project of 1881 was discontinued, because of a new plan for a channel 14 ft. deep from the Great Lakes to the Gulf. The Upper Mississippi carries only a small amount of sediment and was navigable in its natural state to St See also:Paul, although at low water the larger river boats could ascend no farther than La Crosse, Wisconsin. In 1879 Congress adopted a project for obtaining a channel with a minimum depth at low water of 42 ft., chiefly by means of contraction works. In 1907 Congress authorized further contraction, dredging, the construction of a lateral canal at Rock Island Rapids, and the enlargement of that at Des Moines Rapids with a view to obtaining a channel nowhere less than 6 ft. in depth at low water. By means of two locks and dams, which were begun in 1894 and were about three-fourths See also:complete in 1908, a navigable channel of the same depth will be extended from St Paul to Minneapolis. The United States government has constructed dams at the outlets of lakes Winnibigashish, Cass, Leech, See also:Pine, Sandy and Pokegama, and thereby created reservoirs having a total storage capacity of about 95,000,000,000 cub. ft. This reservoir system, which may be much enlarged, is also beneficial in that it mitigates floods and regulates the flow for manufacturing purposes and for logging. Although the United States government has expended more than $70,000,000 on the Mississippi river between the mouth of the Missouri and the head of the passes, the improvement of navigation thereon has not been great enough to make it possible for river freighters to force down railway rates by competition. But it is no longer merely a question of competition. The productivity of this region has become so enormous that See also:railways alone cannot meet the requirements of its commerce, and a persistent demand has arisen for a channel 14 ft. deep from the Great Lakes to the Gulf. The first great impetus to this demand was given in 1900, when a canal 24 ft. in depth, and known as the See also:Chicago Drainage Canal, was opened from the Chicago river to See also:Lockport, Illinois, on the Des Plaines river, 34 M. from Lake Michigan. Two years later Congress appropriated $200,000 for the Mississippi River Commission to make a survey and prepare plans, with estimates of cost, for a navigable waterway 14 ft. in depth from Lockport to St Louis. The commission reported favourably in 1905, and in 1907 Congress provided for another commission, which in June 1909 reported against the 14 ft. channel, estimating that it would cost $128,000,000 for construction and $6,000,000 annually for maintenance, and considered a 9-ft. channel (8 ft. between Ohio and St Louis) sufficient for commercial purposes. The Ohio is commercially the most important tributary, and in flood time most of the commerce on the Lower Mississippi consists of See also:coal and other heavy See also:freight received from the mouth of this river. Its navigation at low water has also been improved by dredging, rock excavation and contraction works. In its upper reaches a channel 9 ft. in depth had been obtained before 1909 by the construction of a number of locks with collapsible dams which are thrown down by a flood. It is the plan of the government to extend this system to the mouth of the river, and it has been estimated that a channel 12 to 14 ft. in depth may ultimately be obtained by a system of See also:mountain reservoirs. Furthermore, the government has given to a See also:corporation a See also:franchise for the connexion of the Ohio at See also:Pittsburg with Lake See also:Erie near See also:Ashtabula, Ohio, by means of a canal 12 ft. in depth. The Missouri is navigable from its mouth to Fort See also:Benton, a distance of 2285 m., and it had become a very important See also:highway of commerce when the first railway, the See also:Hannibal & St See also:Joseph, reached it in 1859. Its commerce then rapidly disappeared, but See also:regular navigation between See also:Kansas City and St Louis was re-established in 1907 and a demand has arisen for a 12-ft. channel from the mouth of the river to See also:Sioux City, See also:Iowa. The Red, Arkansas, See also: In 1817 the commerce from New Orleans to the Falls of the Ohio, at See also:Louisville, was carried in barges and See also:keel-boats having a capacity of 6o to 8o tons each, and 3 to 4 months were required to make a trip. In 1820 steamboats were making the same trip in 15 to 20 days, by 1838 in 6 days or less; and in 1834 there were 230 steamboats, having an aggregate See also:tonnage of 39,000 tons, engaged in trade on the Mississippi. Large numbers of See also:flat boats, especially from the Ohio and its tributaries, continued to carry produce down stream; an extensive canal system in the state of Ohio, completed in 1842, connected the Mississippi with the Great Lakes; these were connected with the See also:Hudson river and the See also:Atlantic Ocean by the Erie Canal, which had been open since 1825. Before the steamboat was successfully employed on the Mississippi the See also:population of the valley did not reach 2,000,000, but the population increased from approximately 2,500,000 in 1820 to more than 6,000,000 in 1840, and to 14,000,000 or more in 186o. The well-equipped passenger boats of the period immediately preceding the Civil War were also a notable feature on the Ohio and the Lower Mississippi. In the Civil War the Lower Mississippi, the Ohio, and its two largest tributaries—the Cumberland and the Tennessee—being still the most important lines of communication west of the Appalachian Mountains, determined largely the movements of armies. The adherence of See also:Kentucky to the Union excluded the Confederacy from the Ohio, but especially disastrous was the fall of See also:Vicksburg and Port Hudson, whereby the Confederacy was cut in two and the entire Mississippi became a Federal high-way. Under Federal control it was closed to commerce, and when the war was over the prosperity of the South was temporarily gone and hundreds of steamboats had been destroyed. Moreover, much of the commerce of the West had been turned from New Orleans, via the Mississippi, to the Atlantic seaboard, via the Great Lakes and by new lines of railways, the number of which rapidly increased. There was, of course, some revival of the Mississippi commerce immediately after the war, but this was checked by the bar at the mouth of the south-west pass. Relief was obtained through the Fads jetties at the mouth of the south pass in 1879, but the facilities for the See also:transfer of freight were far inferior to those employed by the railways, and the steamboat companies did not prosper. But at the beginning of the loth century the prospects of communication with the western See also:coast of North America and South America, and with the Orient by way of an isthmian canal, the inadequate means of transportation afforded by the railways, the efficiency of competing waterways in regulating freight rates, and the See also:consideration of the magnificent system of inland waterways which the Mississippi and its tributaries would afford whenfully See also:developed, have created the strong demand for river improvement. 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