TENNESSEE RIVER, the largest tributary of the Ohio river, U.S.A. It is formed by the confluence of the Holston and the French Broad rivers 4.5m. above Knoxville (Tenn.), flows south south-west to Chattanooga, there turns west through the Cumberland Plateau and into the north-east corner of Alabama, continues west across the northern part of Alabama, turns north on the boundary between Alabama and Mississippi, and continuing north across Tennessee and Kentucky unites with the Ohio at Paducah. Its principal tributaries rise in the Appalachian Mountains ; the Holston and the Clinch on the mountain slopes that flank the Appalachian valley in western Virginia; and the. French Broad, the Little Tennessee and the Hiwassee in the mountains of western North Carolina. The Tennessee itself is 652m. long, and with the Holston and the North Fork of the Holston forms a channel about 9oom. long. Its drainage basin covers about 44,000sq.m., and its low-water discharge at Paducah is 10,60ocu.ft. per second. Its average fall is o.79ft. per m.— 0.956ft. from Knoxville to Chattanooga; i•i9ft. from Chatta nooga to Florence (Ala.), and 0.39ft. from Florence to its mouth. The banks are everywhere easily accessible except at Knoxville and Chattanooga, where, for short distances, high elevations rise precipitously, from the water; and as the banks are mostly of clay or rock the channel is permanent and the river is unusually free from silt. The Tennessee is navigable by steamboats through
, out its entire course of 652m. for several months of the year.
In 1904 the Federal Government authorized the construction, with private capital, of a lock and dam at Hales Bar to provide a channel 6f t. deep between it and Chattanooga, the water-power to be used by the company furnishing the capital. The Colbert and Bee Tree shoals were improved by the Colbert Shoals lock and canal, opened in 1911. In 1917 the U.S. Government undertook the construction of a navigation power dam (Wilson or dam No. 2), 95ft. high at Muscle shoals (q.v.) and by 1926 the work had been completed, except the lock, at a cost of $43,387,709 for con struction and $359,592 for maintenance. A second lock and dam (known as No. 1), below Wilson dam, was completed and put in operation in March 1926, at a cost of $960,515. The Federal Government had spent, up to 1927, about $30,000,000, exclusive of the Muscle Shoals dams, on improving navigation on the Ten nessee and its tributaries. The total commerce carried on the various sections of the Tennessee had, in 2925, an aggregate value of $12,441,364; the commerce of its principal tributaries amounted to