United States Army Corps of Engineers
First established as an arm of the Continental Army, the U.S. Army Corps of Engineers has both military and civil missions. Since the Revolutionary War, it has provided topographic reconnaissance and mapping, fortification design and construction, and related services for American armies overseas and at home. In 1824 the work of the corps in surveying and improving transportation logistics for frontier armies led to its congressional assignment for the improvement of navigation on American rivers and harbors.
Early engineers surveyed and mapped fortification and transportation routes for the advancing army, and these maps and routes proved useful to Tennessee pioneers. Based upon these surveys, Congress approved navigation improvements on the Mississippi, Cumberland, and Tennessee Rivers before the Civil War and assigned the work to the Corps of Engineers. Using open channel clearance engineering before 1860, the corps improved the entire course of the Mississippi River along Tennessee’s western border, the Cumberland from its mouth past Nashville into Kentucky, and the Tennessee River from the Alabama line upstream to Knoxville.
During the Civil War, Confederate army engineers fortified the rivers at Forts Henry and Donelson and established defensive positions at Tennessee’s major cities. After Union forces advanced into Tennessee, their army engineers built elaborate fortifications for the defense of Nashville, Knoxville, Chattanooga, and other cities and constructed new railroads for logistics and defenses for railroad bridges while also conducting reconnaissance and mapping for use of the armies.
During the postwar era, when Congress authorized a massive program for navigation improvements, the corps again applied open-channel clearance engineering to the entire course of the Mississippi and Tennessee Rivers, most of the Cumberland, and many of their tributaries. During this era, the corps also cleared fallen trees, or “snags,” and other obstructions from the Clinch, Powell, Nolichucky, French Broad, Elk, Duck, Red, Obey, Obion, and other streams to provide market access for Tennessee’s agricultural, forest, and mineral resources.
Although open-channel clearance and dredging remained the corps’s method for improving Lower Mississippi River navigation, it adopted canalization for the Tennessee and Cumberland Rivers near the end of the nineteenth century. To provide a minimum six-foot depth for steamboat navigation, the corps built fifteen low timbercrib dams and masonry locks on the Cumberland from its mouth to points upstream of Nashville, ending this project in 1924, when steamboat commerce died. On the Tennessee, near the turn of the century, the corps built two canals with locks around the major obstructions to steamboat commerce at Muscle Shoals and Colbert Shoals in Alabama, relying on open-channel clearance on river sections in Tennessee.
During the 1920s the corps conducted comprehensive studies of the Cumberland, Tennessee, and Mississippi River basins, planning the development of nine-foot channels for towboat-barge commerce, along with flood control, hydroelectric power generation, and allied programs. The pioneering multiple-purpose project was Wilson Dam at Muscle Shoals on the Tennessee River. It was built during the 1920s as one of the nation’s first projects to provide flood control and hydropower benefits in addition to navigation. The corps was implementing its comprehensive plans for the Tennessee River, initiating construction of the Wheeler Dam in Alabama and Norris Dam in East Tennessee, when Congress created the Tennessee Valley Authority (TVA) in 1933 and assigned comprehensive development to TVA. Since the corps had statutory responsibility for navigation, it retained this function on the Tennessee River and the lockmasters at TVA dams are employed by the Corps of Engineers.
During the 1940s the corps managed comprehensive development in the Cumberland Valley and Ohio Valley. In the Cumberland Valley, the corps built a number of multiple-purpose dams for flood control, recreation, and hydropower production–Barkley, J. Percy Priest, Old Hickory, Cordell Hull, Center Hill, and others. The Southeastern Power Commission purchased electric power produced at the corps’s Cumberland Valley dams and sold it at wholesale rates to TVA for distribution to local utility systems.
During World War II the corps purchased land and constructed military installations, munitions plants, and airfields throughout Tennessee. Fort Campbell is the largest of these bases still under army management. Others, such as Sewart Air Force Base at Smyrna, were later returned to civilian management.
The corps created special Engineer Districts during World War II and later for unique projects. Its Kingsport District managed the construction of Holston Ordnance Works for RDX projection, and its Manhattan District purchased the land and managed construction of the Oak Ridge plants and laboratories for nuclear weapons production. After the war, its Tullahoma District built facilities for aerodynamic wind tunnel testing at the Arnold Engineering Center.
The corps essentially completed its multipurpose dam construction program during the 1970s, and the major development completed during the 1980s was the Tennessee-Tombigbee Waterway connecting the Tennessee River near Pickwick Dam with the port of Mobile, Alabama. Shortening the route to the seaboard by hundreds of miles, this waterway aimed to improve Tennessee’s access to international markets, but it has yet to achieve the barge tonnage predicted before its construction.
Since the creation of TVA in 1933, Tennessee has been served by two Engineer Districts, one headquartered at Nashville for the Cumberland River and the other at Memphis for the Mississippi River and its West Tennessee tributaries.
Floyd M. Clay, A Century on the Mississippi: A History of the Memphis District, U.S. Army Corps of Engineers (1976); Leland R. Johnson, Engineers on the Twin Rivers: A History of the Nashville District, Corps of Engineers (1978)