No other river has so vast a drainage-basin: it draws its water supply from twenty-eight States and Territories; from Delaware, on the Atlantic seaboard, and from all the country between that and Idaho on the Pacific slope--a spread of forty-five degrees of longitude.

The Mississippi receives and carries to the Gulf water from fifty-four subordinate rivers that are navigable by steamboats, and from some hundreds that are navigable by flats and keels.

The area of its drainage-basin is as great as the combined areas of England, Wales, Scotland, Ireland, France, Spain, Portugal, Germany, Austria, Italy, and Turkey; and almost all this wide region is fertile; the Mississippi valley, proper, is exceptionally so.
It is a remarkable river in this: that instead of widening toward its mouth, it grows narrower; grows narrower and deeper.

From the junction of the Ohio to a point half way down to the sea, the width averages a mile in high water: thence to the sea the width steadily diminishes, until, at the 'Passes,' above the mouth, it is but little over half a mile.

At the junction of the Ohio the Mississippi's depth is eighty-seven feet; the depth increases gradually, reaching one hundred and twenty-nine just above the mouth.
The difference in rise and fall is also remarkable--not in the upper, but in the lower river.