The Encyclopedia Americana (1920)/Mississippi River

MISSISSIPPI RIVER (Ind. Missi Sepe, “father of waters,” “great river”), the main stem of the greatest drainage system of North America, and one of the greatest in the world (1,257,000 square miles); draining the entire western slope of the Alleghany-Appalachian range, and all the eastern slope of the United States Rockies save a small southern portion, with all between—19 States and two Territories in all, from New York to Montana, but narrowing considerably in the lower basin. The Mississipi extends nearly the entire length of the United States, from within 100 miles of Canada to the Gulf of Mexico, in a watercourse of about 2,550 miles, varied slightly by the lower river bends and cut-offs; and forms the boundary, total or partial, of 10 States—Minnesota, Iowa, Missouri, Arkansas and Louisiana, on the west, and Wisconsin, Illinois, Kentucky, Tennessee and Mississippi, on the east. On its banks are four cities with from 200,000 to 600,000 inhabitants (Saint Louis, New Orleans, Saint Paul and Minneapolis), and 17 others of over 10,000—Winona, Minn.; La Crosse, Wis.; Dubuque, Clinton, Davenport, Muscatine, Burlington and Keokuk, Iowa; Rock Island, Quincy, Alton and Cairo, Ill.; Hannibal, Mo.; Memphis, Tenn.; Vicksburg and Natchez, Miss.; and Baton Rouge, La. It is navigable over 2,000 miles from its mouth to Minneapolis (Falls of Saint Anthony), though the end of regular navigation is Saint Paul, 13 miles below; and is brokenly navigated by smaller steamers to Leech River, 415 miles farther on, along different reaches. It has about 100,000 tributaries, 240 large enough to figure on small-sized statistical charts, 45 of them navigable for distances varying from 2,300 to 50 miles, and aggregating some 15,700 miles of inland navigation; steamers can go upon it and its tributaries some 4,000 miles east and west without breaking bulk—from Great Falls, Mont., on the Missouri, to Olean, N. Y., on the Allegheny. The greatest of the affluents, the Missouri, is usually considered the main stream, being about 1,600 miles longer than the upper Mississippi above the mouth (4,200 miles from the Gulf, the longest river course on the globe), having

a basin more than three times as great, and discharging a considerably larger volume of water annually; nevertheless the upper Mississippi has so much steadier a flow—the Missouri shrinking at low water to 1-48 the volume in flood, and practically unnavigable then—that the former as between the two maintains the permanent navigability of the joint stream, and is justly enough held the main body in popular estimation; besides that the axial valley is continuous. Moreover, the Ohio with its great rainfall (41.5 inches, against 35.2 for the upper Mississippi and 20.9 for the Missouri) discharges far more than either, and if that were valid ground, should itself be held the main stream.

The chief tributaries of the lower Mississippi are as follows, in order of contribution to the volume of water in the lower river: Ohio, 1,300 miles long (to source of Allegheny); width 1,200 feet at Pittsburgh, 3,000 at mouth; basin, 207,111 square miles; annual discharge, about 5,000,000,000,000 cubic feet; per second, 158,000. Missouri, 2,908 miles long; width, 1,500 feet at Fort Benton (head of large-steamer navigation), 3,000 at mouth; basin, 527,690 square miles; annual discharge, 3,780,000,000,000 cubic feet; per second, 120,000. Upper Mississippi, 1,330 miles long; width, 1,200 feet at Saint Paul (head of large navigation), 5,000 at junction with the Missouri, basin 179,635 square miles; annual discharge, 3,300,000,000,000 cubic feet; per second, 105,000. Arkansas, 1,514 miles long; width, 1,500 feet at Fort Smith (head of large navigation), and about the same to its mouth; basin, 184,742 square miles; annual discharge, 2,000,000,000,000 cubic feet; per second, 63,000. Red, 1,200 miles long; width, widely varying from log dams, etc.; annual discharge, 1,800,000,000,000 cubic feet; per second, 57,000. The three next greatest basins are the White, Yazoo and Saint Francis. The total annual discharge, including three outlet bayous, is 21,300,000,000,000 cubic feet, or 675,000 per second.

The following are the distances from the farthest sources on the main stem to the chief landmarks on its course, and the mean-water elevations above sea-level at the end of the reaches:

The “source” of a great river is often a term of little import, as its waters may gather from the drainage of a large district; but taking it in its current sense, of the ultimate reservoir of its farthest extension, the Mississippi rises in the basin draining into (q.v.) in northern Minnesota. Into the west arm flows from the heights, through a couple of small ponds, a stream of considerable power and fullness, called by its discoverer Nicollet the “Infant Mississippi,” and now confirmed as such so far as there is one ultimate stream; and out of it, from the north arm, flows the Mississippi. Nicolett in 1836 found it 16 feet wide and 14 inches deep at the outlet. Government Commissioner J. V. Brower in 1893 found it 50 feet wide and three or four feet deep in mid-channel, with a muddy bottom and a current of about two miles an hour. As the current increases it narrows to some 30 feet; is filled with débris, shoals and boulders; and for some distance down the stream free passage with canoes is impeded by reeds, flag and water grass. It continues northward with slight falls and rapids to Lac Travers or Bemidji, about 10 miles long by 4 feet wide, set in a basin surrounded by forested hills and with a beach of perfectly white sand. Thence it issues on the east, and for 25 miles southeastwardly brawls over a series of rapids, from whose foot it flows in a clear even stream 120 feet wide and four or five deep to Cass Lake, twice as large as Bemidji; thence on the east six miles to Winnibigoshish, still larger, whence it issues again on the east 172 feet wide, and as before grows narrower, deeper and of swifter current as it drains the marshes and meadows below. Just above the junction with Leech River, the outlet of the noble Leech Lake, the largest in this region — 25 by 15 miles — it strikes a bed of sandstone with a fall of 20 feet in one-sixth of a mile, and is ruffled into rapids called the Falls of Pokegama, in a channel 80 feet wide. This is about 130 miles from the source; small steamers run to the foot of the rapids. Thence it runs crookedly with a general south trend, about 120 feet wide, through hardwood forests, swamps and sandhills, covered with glacial gravel and boulder drift. From the entrance of Swan River to that of the outlet of Sandy Lake there are six rapids; the latter lake has a small stream running from a small pond to the eastward, not far from Saint Louis River, emptying into Lake Superior at Duluth, and forms the old canoe route from Minnesota to the Great Lakes. Thence to the entrance of Pine River, about 150 miles from the Pokegama Falls, it has numerous rapids and is broad enough to enclose several islands; it receives several smaller tributaries; and the powerful Crow Wing River, 47 miles below Pine River, also fed from a district of lakes, contributes almost as much volume to the joint stream as the Mississippi itself. At the Sauk Rapids, a mile long, 133 miles below the Crow Wing and at the entrance of Sauk River, begin the first rocky banks of Potsdam sandstone, extending down to Rock Island.

At the Falls of Saint Anthony, 80 miles below, the river descends about 65 feet in three-fourths of a mile, forming rapids interrupted in the middle by a precipice 18 feet high, over

which the river, now 1,200 feet wide, formerly plunged in a cataract of great beauty and fame. An island divided it into two channels, the western being the larger. Here the water power has been used to build up the immense manufacturing interests of Minneapolis. Thirteen miles below a convenient landing has established Saint Paul as the head of continuous navigation for large steamers and made it the great wholesale distributing point for the Northwest, and onward the valley is richly fertile, very beautiful and often of much grandeur. Below Saint Paul the river widens into the island-studded “Lake” Pepin. From Davenport, Iowa, 943 miles from the source, to Rock Island, 14 miles below, there are rapids of 22 feet fall, formerly obstructing the navigation; the government has now cut a channel in the solid rock. The formation of the bed is peculiar; it consists of stratified limestone, crushed into folds which form a series of six or seven parallel bars across the channel, one to three miles apart. From this point onward the formation is carboniferous and the banks rise into picturesque rocky bluffs sometimes 300 feet high, as far down as nearly to the beginning of the alluvial region, 140 miles below Saint Louis. At the mouth of the Des Moines River, 130 miles below Rock Island, is another rapid of 24 feet fall, now avoided by a ship canal; and between Muscatine and Keokuk is one 12 miles long, with 23 feet descent. Nearly 200 miles below Keokuk the first great change comes to the river. Into this clear placid stream is poured a swift, muddy, red torrent, at high water of far greater volume than its own, that of the enormous Missouri, creating turbulent eddies, and for many miles flowing side by side with the white northern stream without mixing of waters. The bends and winds of the river, making the current cross from side to side, finally mingling them within 100 or 150 miles. Not quite 200 miles farther on comes in the mighty Ohio, with a volume over two-thirds as great as that of the other two united.

But 30 miles above here and three miles above the great geological landmark of Cape Girardeau, Mo., begins a still greater change: the vast northern upland, mainly elevated rock with a moderate soil covering it, which has been drained by the river, ceases. The remaining 1,100 miles of its valley is the creation of its own silt, through which it meanders in deep curves and loops and narrow horseshoes, shifting its channel capriciously, continually building up one side and cutting away the other, but rarely twice the same side. Cape Girardeau is an ancient headland of an ancient ocean, into which the silt-laden river poured its deposits as the present river docs into the Gulf, and which has receded, leaving more than 1,000 miles of the garden of the world. And the relation of the river to its bottoms is reversed also. From the Falls of Saint Anthony to the end of the uplands are deep strips of bottom land overflowed at high water; but except at such periods they are above the river. But in the lower bottoms made by the river itself, the surface of the latter is normally above that of the bordering lands. The friction of the current on the sides and bottom causes the water held back to keep depositing fresh layers of the heavier sediment on the edges and in the channel; so that as the depth of water

remains the same and the channel continually shallows, the surface of the water must rise and would at last empty itself did not the same process elevate its retaining walls. The river therefore runs in a groove, cut into a ridge considerably above the surrounding country, its surface much higher and its bed much lower than the region for many miles back; it slopes away with a gradient at first of about seven feet to the mile, decreasing regularly to the outer edges of the flood plain — which at the Ohio is about 10 miles wide and 50 to 70 in lower Louisiana, widening to 150 at the Delta — and ending at about six inches per mile in the swamps and bayous at the outer edge. The natural method of discharging the waters at flood seasons is to overflow the banks and flood the adjacent country, part of the waters flowing off through semi-river channels (bayous) in the soft earth, the rest remaining in pools and swamps and gradually evaporating; and the attempt to keep it in the same channel which suffices for low water, to comport with the needs of civilized occupancy, has produced an excessively costly battle with nature, of which the success is by no means yet assured or assurable.

The junction of the Red introduces us to still another phenomenon. That great river formerly discharged its main waters to the Gulf through the Atchafalaya “Bayou,” roughly parallel with the Mississippi; but that and the Mississippi both sent their surplus waters through an amazing network of lesser bayous, which still penetrate southern Louisiana with thousands of miles of navigable channels. The head of the Atchafalaya silted up and became choked with logs and rubbish, and the Red opened a channel into the Mississippi; later in the 19th century the government dredged out the head of the bayou to make a navigable channel; it rapidly widened to a great river, became again the main channel of the Red and threatened to ruin a great district of fertile plantations, so that works had to be undertaken to prevent its enlargement. As we approach the place where the Mississippi plain merges in the great coastal plain of the Atlantic, the surface grows lower and the soil spongier; and the river (which above the Mississippi is about a mile wide, thence to the Red half a mile to a mile, with occasional reaches of a mile and a half, and below the Red narrows to a width of about 3,000 feet, which it retains with curious persistence) widens to about a mile and a half and enters the Gulf — through the Delta, a quaking, impassable, finally half liquid salt marsh land in process of making — by three great arms or “passes,” of which two ramify still further. These are known as the Southwest Pass, the South Pass (with two arms near the Gulf) and an eastern arm soon dividing into North Pass and Pass à l'Outre.

It should be said, however, that these alluvial bottoms do not quite monopolize the space from the Ohio to the Gulf. Here and there on the east bank there are spots where high solid ground, old capes and peninsulas of the antique ocean, come down to the river side; as at Columbus, Ky., Randolph and Memphis, Tenn., Vicksburg, Grand Gulf and Natchez, Miss., and Baton Rouge, La. With one exception, each of these spots has been utilized as a considerable

road for the commerce of the interior to the great waterway.

Improvements of the River.— These are broadly divisible into two classes: those designed to improve navigation and those designed to prevent overflows. From 4 March 1789 to 30 June 1886, a period of 97 years, in the improvement of the Mississippi and its 44 navigable tributaries, the Federal government expended a total sum in round numbers of about $57,000,000. The control of the waters of the Mississippi so as to make the navigation of the river safe and so as to make the immediately surrounding country fit for agriculture has been an economic problem of more than merely local interest. The problem is national historically, for to the control of the Mississippi as much as to any other one thing the historical growth of the country is due. It is even more strikingly true that the problem is of national significance from the commercial point of view, simply because this vast river drains the richest territory in the world, 70 per cent of the area of the United States. Among the older methods of control was that of narrowing the channel to deepen the available water. This operation involved closing off side channels around islands, etc. — stopping up the heads, diking off small bays and inlets, strengthening caving banks and obstructing the side current by solid spur dikes, set obliquely out into the stream nearly to the channel line. After the entrance of the Missouri, the mass of sediment furnishes a new and effective weapon. Between here and Cairo hurdles of piles and brush are laid along the banks, jetty fashion; the sediment packs into the brush and speedily becomes solid, and the results in creating new banks to narrow the channel have been most gratifying, besides reclaiming large tracts of overflowed bottom lands. Caving banks are protected by mattresses; the depth of water being slight, they are made lighter than in the lower river. Below Cairo the work is of the same nature, but more difficult from the volume of water and the alluvial lands easily crumbling. Here the channel is narrowed, where it exceeds about 3,500 feet, by mattresses from 800 to 2,000 feet long and 200 to 300 feet wide, weighted down with rubble stone. But the immense weight of water, which may be from 60 to 100 feet deep at flood, has forced their continual increase in weight and strength of construction. The brush and small saplings have been replaced by fascines (solid rods tightly withed together), the binding poles by strong wire; the cost per foot of bank protection trebling in 25 years, from about $10 to $30. For closing off side channels and watercourses, rows of piles are driven in, 8 or 10 feet apart and the rows 20, and the upper row interwoven with brush. Caving banks are graded down to a slope and faced with mattresses; of late, however, rubble stone has been used with better success. On the lower river, where stone has to be brought from long distances, concrete has been experimented with.

Another system is that of levees. Formerly, under the slave system, each planter along the rivers liable to overflow had rude dikes erected for himself; the importance of the work to neighborhoods led to common town action, then to county and State action. These levee systems, of course, were broken

through in floods, but the water rose only to its natural height in the channel and soon subsided; and to furnish absolute security against overflow would cost not only an enormous sum but would exceed a hundredfold the capital value of the districts imperiled. When in 1879 Congress appointed the Mississippi River Commission, it forbade them to consider the protection of lands from overflow as part of their work. Nevertheless a majority of the commission believed that the levee system could be used efficiently to improve navigation, and estimated that $11,443,000 below Cairo would furnish a complete protection for the banks and double the depth of permanent river channel, by the natural scour of the water as with jetties. The level of the river has risen with the levees over six feet and is estimated to ultimately reach 11 when the levee system has made a smooth solid bank all the way, with no place for overspill. These levees are from 8 to 14 feet high, with a width on top of eight feet and a side slope of one-third; they project three feet above high water, but need to be raised every few years as the river rises. They have to be placed near the banks to protect riverside plantations and avoid the slope away from the river; and very large amounts of them have to be replaced yearly from cave-ins.

The Act of 28 June 1879, by which the commission was created, defines its duty in part as follows:

Under the authority of this and subsequent acts making appropriations and relating to the subject, surveys and observations have been carried on and works of improvement under the authority and direction of laws making appropriation for that purpose have been undertaken and executed. The original project contained in the report of the Mississippi River Commission dated 17 Feb. 1880 contemplated the permanent fixing and improvement of the channel to a depth of at least 10 feet at extreme low water by the construction of the low-water width to about 3,000 feet, the protection of the banks against caving and the control of the flood water by means of levees. This report was the one upon which Congress made its first appropriation for the improvement of the Mississippi River under commission plans, thereby officially adopting such plans for the inauguration of this work.

When the Mississippi River Commission began the work of improvement there were few, if any, precedents of practical value to serve as guides in a project of such magnitude. But very meagre data as to the regimen of the river were available, and a thorough knowledge of its many varying phases was essential before satisfactory comprehensive plans of improvement could be developed. Exhaustive surveys and observations of the physics of the river

from the headwaters to the mouth were therefore inaugurated and carried on until the data needed were secured and experiments with various kinds of plant and material were also made in order to develop the equipment and type of construction needed for efficient work. This work occupied several years. During these years the appropriations were comparatively small, and sometimes failed altogether, with disastrous results to the channel works, so progress was necessarily slow. As a result of the knowledge of the regimen of the river acquired and the lesson taught by the experimental work, definite projects are now entered upon with confidence of success, but efforts looking to improved methods to secure greater efficiency and economy will be continued.

The earlier works were designed primarily for the rectification and improvement of the channel, and were confined to the Plum Point Reach, 147 to 186 miles, and Lake Providence Reach, 517 to 552 miles below Cairo. These reaches were selected because here the shifting sand bars and deficient depths were most pronounced and the low-water navigation most difficult. Highly beneficial results were obtained in the improvement of the channel depths in those reaches, and the work done in them confirmed the soundness of the theory upon which it was based, but also demonstrated that more substantial types of construction were needed and that the permanent improvement of the channel by contraction and revetment works would consume a long period of time, while the pressing needs of commerce called for immediate relief. The development in hydraulic dredging machinery had reached such a stage at this time as to hold out the hope that an immediate and economical solution of the problem of temporarily deepening the channel for navigation purposes might be found in the opening and maintenance of channels across the obstructing bars at each low-water season by means of dredging. After extended studies and experiments, hydraulic dredges of large capacity adapted to the peculiar service required were developed by the commission and this method of temporary improvement of the low-water channel was adopted with a view of maintaining a navigable channel not less than 250 feet in width and 9 feet in depth, and has been applied with success.

Since the adoption of dredging, the permanent work of channel improvement has been confined to the revetment of banks, and a type of revetment has been developed which successfully withstands the scouring action of the river. Concrete has been largely substituted for the upper bank revetment, and its use for sinking the present type of willow mat, as well as a possible substitute for the mat itself, is being tried out with a view to further economy and increased efficiency.

The extent of bank revetment is, however, relatively so great when compared to the funds available for its construction that it has been necessary to confine the work to cases of urgent necessity, such as caving banks which threaten cut-offs or the safety of large levees which could only be replaced at excessive cost, and the harbor fronts of cities. Substantial revetment for the purpose of fixing the banks of the river is essential to any successful scheme of improvement, and as the project adopted by

Congress requires that the commission shall “correct, permanently locate and deepen the channel and protect the banks of the Mississippi River,” large increase in expenditures for revetment construction are urgently needed.

An important item in the operation of the commission is the construction and general repair of levees, which was first authorized without qualifying restrictions by the Act of 19 Sept. 1890; and since that date about one-half of the appropriations made by Congress have been devoted to that purpose.

Briefly stated in general terms and quoting in part the several acts of Congress under which the project is being carried out, the work now in progress covers the Mississippi River from Rock Island, Ill., to the Head of the Passes, 1,568 miles, “the Ohio River from its mouth to the mouth of the Cache River,” and “the Arkansas River between its mouth and the intersection thereof with the division line between Lincoln and Jefferson counties,” and it includes:

Since the creation of the Mississippi River Commission in 1879 there has been appropriated and allotted for expenditure under it on the Mississippi River and its tributaries to 1917, $96,375,610.68.

Consult Anderson, A. D., ‘The Mississippi and its Forty-four Navigable Tributaries’ (Washington 1890); Chambers, J., ‘The Mississippi River and its Wonderful Valley; Twenty-seven Hundred and Seventy-five Miles from Source to Sea’ (New York 1910); Ocken, ‘The Mississippi: Some of its Physical Characteristics’ (1900); Clemens, ‘Life on the Mississippi’ (1883); ‘Mississippi River Commission’ in Annual Report, Chief of Engineers, United States Army, War Department (Washington, D. C, 1879-1918).