The Tennessee valley authority was established in 1933 by president Roosevelt as a way to provide jobs and electricity to the impoverished Appalachian region. The Tennessee Valley is an area of approximately 41,000 square miles and lies mostly in Tennessee but also includes parts of the six other states: Kentucky, Virginia, North Carolina, Georgia, Alabama and Mississippi.

As World War II broke out, the TVA began one of the largest hydropower construction programs ever undertaken, to provide power for critical war industries. The main industry located in the valley was Alcoa (the Aluminum Company of America) south of Knoxville, which during the war was the largest aluminum manufacturer in the world, providing aluminum to bomb and airplane factories throughout the country.During its construction peak in 1942, 12 hydroelectric projects and a steam plant were under construction at the same time, and over 28,000 were employed in their design and construction.

The TVA power was also critical for the work of a secret project set up in an just south of Norris Dam in 1942. It was part of a larger effort code-named the Manhattan Project—the program that produced the first atomic bomb. To manufacture the nuclear materials needed for the bomb, the government built an entire city called Oak Ridge in the hills of Tennessee. The location was chosen for two reasons, because of its proximity to the TVA dams which could produce the massive amount of power needed to fuel the elements of nuclear-materials production: the centrifuge and the electromagnetic and gaseous-diffusion processes. But also because of its location near a fresh water source, required for cooling the heat intensive Nuclear-materials production, Oak Ridge could satisfy both requirements. For three years the Manhattan Project worked 24 hours a day towards its goals, using millions of kilowatts of TVA energy for a project that wasn’t even publicly acknowledged until August 1945, when the bombs dropped on Hiroshima and Nagasaki.

Norris Dam was completed in 1936 and Fontana dam in 1944, click for a photographic survey of each.

information used for this overview is from the TVA official website and libary of congress sources, http://www.tva.gov