Mississippi

Mississippi 5 River, the central artery of the river system which drains the greater part of the United States of America lying between the Appalachian Mountains on the east and the Rocky Mountains on the west. It rises in the basin of Itasca Lake, in northern Minnesota, and flows mostly in a southerly direction to the Gulf of Mexico. In the region of its headwaters are numerous lakes which were formed by glacial action, but the river itself was old before the glacial 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 Wisconsin, in contrast with the precipitous bluffs of hard rock on the edges of a valley that is narrow and steep-sided farther down where the river was turned from its ancient course by the glacier. So long as the outlet of the Great Lakes through the St Lawrence Valley was blocked by the icy mass, they were much larger than now and discharged through the Wabash, Illinois and other rivers into the Mississippi. Below the glaciated region, that is from southern Illinois to the Gulf, the river had carved before the close of the glacial period a flood-plain varying in width from 5 to 80 m., but this has been filled to a depth of Ioo ft. or more with alluvium, and in the postglacial period an inner valley has been formed within the outer one. The total length of the river proper from the source near Lake Itasca to its mouth in the Gulf of Mexico is 2 553 m.; but the true source of the river is at the fountain-head of the Missouri, in the Rocky Mountains, on the S.W. border of Montana, 8000 ft. above the sea, and from this source there is a continuous stream to the Gulf which is 4221 m. long - the longest in the world. The Mississippi and its tributaries have more than 15,000 m. of navigable waterways and drain an area of approximately 1,250,000 sq. m. The system extends through the heart of the continent and affords a direct line of communication between temperate and tropical regions. Certain physical and hydrographic features, however, make the regulation and 1 Removed from office by Federal troops, 22nd of May 1862; W. L. Sharkey was appointed provisional governor by President Johnson.

Removed from office by U.S. troops 55th of June 1868. Resigned 30th of November 1871.

4 Resigned 29th of March 1876; succeeded by the president of the senate.

6 The name is from the Algonkin missi-sepe, literally "father of waters." control of the Mississippi below the influx of the Missouri an exceedingly difficult problem.

The Upper Mississippi, that is the Mississippi from its source to the mouth of the Missouri, drains 173,000 sq. m., over which the annual rainfall averages 34.7 in., and its discharge per second into the Lower Mississippi varies from 25,000 cub. ft. to 550,000 cub. ft. The Missouri drains 528,000 sq. m., over which the annual rainfall averages 19.6 in., and its discharge per second into the Mississippi varies from 25,000 cub. ft. to 600,000 cub. ft. The Ohio drains 214,000 sq. m., over which the annual rainfall averages 43 in., and its discharge per second varies from 35,000 cub. ft. to 1,200,000 cub. ft. The Arkansas drains 161,000 sq. m., over which the annual rainfall averages 28.3 in., and its discharge per second varies from 4000 cub. ft. to 250,000 cub. ft. The Red drains 97,000 sq. m., over which the annual rainfall averages 38.3 in., and its discharge per second varies from 3500 cub. ft. to 180,000 cub. ft. These and a few smaller tributaries produce a river which winds its way from Cape Girardeau, Missouri, to the passes through a flood plain averaging about 40 m. in width and having a general southern slope of 8 in. to the mile. The general lateral slope towards the foothills is about 6 in. in 5000 ft., but the normal fail in the first mile is about 7 ft. Thus the river sweeps onward with great velocity, eroding its banks in the bends and rebuilding them on the points, now forming islands by its deposits, and now removing them. Chief among the changes is the formation of cut-offs. Two eroding bends gradually approach each other until the water forces a passage across the narrow neck. As the channel distance between these bends may be many 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 deposit, and forms in a few years one of the 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 surface at the lowest stage is only 51 ft. above the level of the Gulf, where the mean tidal oscillation is about 15 ft. The river channel in this section is therefore a fresh-water lake. At the flood stage the surface rises 50 ft. at the mouth of Red river, but of course retains its level at the Gulf, thus givingthe head necessary to force forward the increased volume of discharge. Above the mouth of the Red river the 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 comparative volumes which pass through the channel. At New Orleans the maximum discharge hardly reaches 1,200,000 cub. ft. per second, and a rising river at high stages carries only about ioo,000 cub. ft. per second more than when falling at the same absolute level; but just below the mouth of the Ohio the maximum flood volume reaches 1,400,000 cub. ft. per second, and at some stages a rising river may carry one-third more water than when falling at the same absolute level. The river is usually lowest in October. It rises rapidly until checked by the freezing of the northern tributaries. It begins to rise again in February, as a consequence of the storms from the Gulf which traverse the basin of the Ohio, and attains its highest point about the 1st of 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 time in June by the late spring and early summer rains in the Missouri basin. As a rule the river is above mid-stage from January to August inclusive, and below that level for the remainder of the year.

## Engineering Works

Below Cape Girardeau there are at least 29,790 sq. m. of rich bottom lands which require protection from floods, and this has been accomplished to a great extent by the erection of levees. The first levee was begun in 1717, when the engineer, Le Blond de La Tour (d. about 1725) erected one a mile long to protect the infant city of New Orleans from overflow. Progress at first was slow. In 1770 the settlements extended only 30 m. above and 20 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 1850 a great impulse was given to systematic embankment by the United States 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 Louisiana. The aid of the government was invoked, and Congress immediately ordered the necessary investigations and surveys. This work was placed in charge of Captain (later General) Andrew A. Humphreys (1810-1883), and an elaborate report covering the results of ten years of investigation was published, just after the outbreak of the Civil War in 1861. In this report it was demonstrated that the great bottom lands above the Red river, before the construction of their levees did1871-1874-1874-18761876-1882-1882-18901890-1896-1896-19001900-1904-1904-1908 1908 not, as had been supposed, in Louisiana, serve as reservoirs to diminish the maximum wave in great flood seasons. Furthermore, 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 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 concert upon defective plans, and a great flood early in 1874 inundated the country, causing terrible suffering and loss. Congress, then in session, passed an act creating a commission of five 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 bank. This system comprised: (1) a main embankment raised to specified heights sufficient to restrain the floods; and (2) where reasonable security against caving required considerable areas near the river to be thrown out, exterior levees of such a height as to exclude ordinary high waters, but to allow 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 determine 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 low-water navigation of the river below the mouth of the Ohio. A board of five army engineers, appointed in 1878 to consider a plan of relief, reported that a depth of 10 ft. could probably be secured by narrowing the wide places to about 3500 ft. with hurdle work, brush ropes or brush dykes designed to cause a deposit of sediment, and by protecting caving banks by 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 commerce. The river naturally discharges through three principal branches, the south-west pass, the south pass and the north-east pass, the latter through two channels, the more northern of which is called Pass a l'Outre. In the natural 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 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 majority approving a ship canal. In 1874 Congress constituted a special board which, after visiting 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 Meuse; and in 1875 Captain James B. Eads (1820-1887) and his associates were authorized by Congress to open by contract a deep channel through the south pass upon the general plan proposed by this board. As modified in 1878 and 1879 the contract called for the maintenance for twenty years of a channel through the pass and over the bar not less than 26 ft. in depth throughout, a width of not less ` than 200 ft. and with a middle depth of 30 ft. The work was begun on the 2nd of June 1875. The required depth was obtained in 1879, and with few interruptions has been maintained. 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 deepwater 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, woven like basket-work, were sunk on the portion of the bank at the time under water, by throwing rubble stone upon them, an excess of stone being used. A common size of mattress was 800 ft. long, counted along the bank, by 250 ft. wide. Sometimes a width of 300 ft. was used, and lengths have reached 2000 ft. The depth of water was often from 60 to loo ft. At first these mats were light structures, but the loss of large quantities of bank protection by the caving of the bank behind them, or by scour at their channel edges, forced the commission steadily to increase the thickness and strength of the mattress, so that the cost of the linear foot of bank protection, measured along the bank, rose from $8 or $10 to $30 in the later work. The contraction works adopted were systems of spurs or pile dykes, running out from the shore nearly to the line of the proposed channel. Each dyke consisted of from one to four parallel rows of piles, the interval between rows being about 20 ft. and between piles in a row 8 or 10 ft. The piles and rows were strongly braced and tied together, and in many cases brush was woven into the upper row, forming a hurdle, in order further to diminish the velocity of the water below the spur. By 1893 it was evident that the cost, which had been estimated at $33,000,000 in 1881, would really be several times that amount, and that the works would require heavy expense for their maintenance and many years for their execution. Navigation interests demanded more speedy relief. The commission then began experimenting with 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 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 sand per hour, the velocity in the 32to 34-in. discharge pipes being from 10 to 15 ft. per second. They cost from $86,000 to $120,000, and their working during a low-water season 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 250 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 latitude of 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 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 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 30th of June 1908 had been increased to 219,621,594 cub. yds., of which the United States had built about one-half, and has expended on them $22,562,544. The length of the levees is about 1486 m., and they are continuous save where interrupted by tributaries or by high lands, from New Madrid, or 80 m. below Cairo, to Fort 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 lie usually near the bank of the river; secondly, to avoid the lower ground, which, owing to the peculiar formation, is found as one goes back from the river. Another 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 $150,000 per mile, to protect a levee perhaps 16 ft. high costing about $30,000 per mile. The levees have top widths of 8 ft., side slopes of one-third, and banquettes when their heights exceed about 10 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 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 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 obstructed 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 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 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 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, 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 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 Chicago Drainage Canal, was opened from the Chicago river to 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 coal and other heavy 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 mountain reservoirs. Furthermore, the government has given to a corporation a franchise for the connexion of the Ohio at Pittsburg with Lake Erie near Ashtabula, Ohio, by means of a canal 12 ft. in depth. The Missouri is navigable from its mouth to Fort Benton, a distance of 2285 m., and it had become a very important highway of commerce when the first railway, the Hannibal & St Joseph, reached it in 1859. Its commerce then rapidly disappeared, but regular navigation between 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 Sioux City, Iowa. The Red, Arkansas, White, Tennessee, and Cumberland rivers, which are parts of the Mississippi system, have each a navigable mileage exceeding 600 m.

## History

Although the Mississippi river was discovered in its lower course by Hernando 'de Soto in 1541, and possibly by Alonso Alvarez de Pineda in 1519, Europeans were not yet prepared to use the discovery, and two Frenchmen, Louis Joliet and Father Jacques Marquette, first made it generally known to the civilized world by a voyage down the river from the mouth of the Wisconsin to the mouth of the Arkansas in 1673.1 In 1680 Louis Hennepin, sent by La Salle, who planned to acquire for France the entire basin drained by the great river and its tributaries, explored the river from the mouth of. the Illinois to the Falls of St Anthony, where the city of Minneapolis now stands, and two years later La Salle himself descended from the mouth of the Illinois to the Gulf, named the basin "Louisiana," and took formal possession of it in the name of his king, Louis XIV. By the war which terminated (1763) in the Treaty of Paris, Great Britain wrested from France all that part of the basin lying east of the middle of the river (except the island of New Orleans at its mouth), together with equal rights of navigation; and the remainder of the basin France had secretly ceded to Spain in 1762. During the War of Independence the right to navigate the river became a troublesome question. In 1779 the Continental Congress sent John Jay to Spain to negotiate a treaty of commerce, and to insist on the free navigation of the Mississippi, but the Spanish government refused to entertain such a proposition, and new instructions that he might forego that right south of 31° N. latitude reached him too late. While the commissioners from Great Britain and the United States were negotiating a treaty of peace at Paris, Spain, apparently supported by France, sought to prevent the extension of the western boundary of the United States to the Mississippi, but was unsuccessful, and the United States acquired title in 1783 to all that portion of the basin east of the middle of the river and north of 31° N. lat. In 1785 Congress appointed John Jay to negotiate a commercial treaty with Don Diego de Gardoqui, the Spanish minister to the United States, but the negotiations resulted in nothing. For the next ten years the Spaniards imposed heavy burdens on the American commerce down the Mississippi, but in 1794 James Monroe, the United States minister to France, procured the aid of the French government in further negotiations, for which Thomas Pinckney had been appointed envoy extraordinary, and in 1795 Pinckney negotiated a treaty which granted to the United States the free navigation of the river from its source to the Gulf and the privilege of depositing American merchandise at the port of New Orleans or at some other convenient place on the banks. Spain retroceded Louisiana to France in 1800, but the Louisiana Purchase in 1803 left very little of the Mississippi basin outside of the United States.

As the headwaters of the river were not definitely known, the United States government sent Zebulon M. Pike in 1805 to explore the region, and on reaching Leech Lake, in February 1806, he pronounced that the main source. In 1820 Lewis Cass, governor of Michigan territory, which then had the Mississippi for its western boundary, conducted an expedition into the same region as far as Cass Lake, where the Indians told him that the true source was about 50 m. to the W.N.W., but as the water was too low to proceed by canoe he returned, and it remained for Henry Schoolcraft, twelve years later, to discover Lake Itasca, which occupies a low depression near the centre of the basin in which the river takes its rise. Jean N. Nicollet, while in the service of the United States government, visited Lake Itasca in 1836, and traced its principal affluent, since known as Nicollet's Infant Mississippi river, a few miles S.S.W. from the lake's western arm. Jacob Vradenberg Brower (1844-1905), who was commissioned by the Minnesota Historical Society in 1889 to make a more detailed survey, traced the source from Nicollet's Infant Mississippi to the greater ultimate 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 state of Minnesota created Itasca State Park, which contains both Itasca Lake and its affluents from the south.

1 It seems probable that Joliet and Marquette were preceded by two other Frenchmen, Pierre Esprit Radisson and Menard Chouart 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.

From the close of the 17th century until the building of the first railways in the Mississippi basin, in the middle of the 19th century, the waterways of the Mississippi system afforded practically the only means of communication in this region. During the early years of the French occupancy trade with the Indians was the only important industry, and this was carried on almost wholly with birch canoes and a few pirogues; but by 1720 immigrants were coming in considerable numbers both by way of the Great Lakes and the mouth of the Mississippi, and to meet the demands of a rapidly expanding commerce barges and keelboats were introduced. The development of the Mississippi Valley must have been slow until the railways came had it not been for the timely application of the power of steam to overcome the strong current of the Lower Mississippi. Even without the steamboat, however, the Mississippi was indispensable to the early settlers, and the delay of the United States in securing for them its free navigation resulted in threats of separation from the Union. The most formidable movement of this kind was that of 1787-1788, in which James Wilkinson, who had been an officer in the War of Independence, plotted for a union with Spain. Steamboat navigation on this river system was begun in 1811, when the "New Orleans," which had been built by Nicholas Roosevelt (1767-1854), made the trip from Pittsburg to New Orleans, but it was six years later before the steamboat was sufficiently improved to ascend to St Louis. In 1817 the commerce from New Orleans to the Falls of the Ohio, at Louisville, was carried in barges and keel-boats having a capacity of 60 to 80 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 tonnage.of 39,000 tons, engaged in trade on the Mississippi. Large numbers of 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 Hudson river and the Atlantic Ocean by the Erie Canal, which had been open since 1825. Before the steamboat was successfully employed on the Mississippi the 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 1860. 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 Kentucky to the Union excluded the Confederacy from the Ohio, but especially disastrous was the fall of Vicksburg and Port Hudson, whereby the Confederacy was cut in two and the entire Mississippi became a Federal highway. 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 Eads jetties at the mouth of the south pass in 1879, but the facilities for' the 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 10th century the prospects of communication with the western 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 consideration of the magnificent system of inland waterways which the Mississippi and its tributaries would afford when fully developed, have created the strong demand for river improvement.

Bibliog Ra Phy.-A. P. C. Griffin, The Discovery of the Mississippi: a Bibliographical Account (New York, 1883); J. G. Shea, The Discovery of the Mississippi, in Report and Collections of the State Historical Society of Wisconsin, vol. vii. (Madison, 1876); J.V. Brower, The Mississippi River and its Sources: a Narrative and Critical History of the Discovery of the River and its Headwaters (Minneapolis, 1893); F. A. Ogg, The Opening of the Mississippi: a Struggle for Supremacy in the American Interior (New York, 1904); E. W. Gould, Fifty Years on the Mississippi; or, Gould's History of River Navigation  (St Louis, 1889); J. W. Monette, The Progress of Navigation and Commerce on the Waters of the Mississippi River and the Great Lakes, in the Publications of the Mississippi Historical Society, vol. vii. (Oxford, Miss., 1903); R. B. Haughton, The Influence of the Mississippi River upon the Early Settlement of Its Valley, in the Publications of the Mississippi Historical Society, vol. iv.; Mark Twain, Life on the Mississippi (Boston, 1883); A. A. Humphreys and H. L. Abbot, Report on the Physics and Hydraulics of the Mississippi River (Philadelphia, 1861); Annual Reports of the Mississippi River Commission (Washington, 1880 sqq.); E. L. Corthell, A History of the Jetties at the Mouth of the Mississippi River (New York, 1881); J. A. Ockerson, The Mississippi River: Some of its Physical Characteristics and Measures employed for the Regulation and Control of the Stream (Paris, 1900); J. L. Mathews, Remaking the Mississippi (Boston, 1909); R. M. Brown, "The Mississippi River from Cape Girardeau to the Head of the Passes," in Bulletins of the American Geographical Society, vols. xxxiv. and xxxv. (New York, 1902 and 1903); J. L. Greenleaf, "The Hydrology of the Mississippi," in the American Journal of Science, vol. ii. (New Haven, 1896); L. M. Haupt, "The Mississippi River Problem," in Proceedings of the American Philosophical Society, vol. xliii. (Philadelphia, 1904).