In 1930, the U.S. Corps of Engineers was directed to complete an engineering survey of the Tennessee River to determine the feasibility of establishing complete river navigability. The resulting report recommended a series of nine main river dams and several tributary dams to allow for a minimum eight foot channel (standard for barge navigation) from Knoxville to Paducah.
U.S. Army Corps of Engineers
Not only was Dunlap's Creek Bridge the first cast-iron bridge in America, it was the first metal bridge anywhere to use what its builder, Capt. Richard Delafield, U.S. Army Corps of Engineers, described as "standardized, interchangeable, manufactured parts." The bridge was built as part of the federal government's effort to make repairs on the National Road before handing authority over to the states. Dunlap's Creek at Brownsville was an especially troublesome crossing, having destroyed three previous bridges since 1801.
The Dismal Swamp Canal was created as a 22-mile waterway, extending from Deep Creek, Virginia to South Mills, North Carolina. The canal enabled North Carolina producers of building and agricultural products to deliver goods to the Port of Norfolk where they were transferred to ocean-going vessels.
Before the Davis Island Lock & Dam were built, the flow of the Ohio River slowed to little more than a trickle during dry periods. For several months each year, the unreliable flow stranded Pittsburgh's steamboats, towboats, and barges.
The Davis Island Lock & Chanoine Dam experimental project was the first lock and dam ever constructed on the Ohio River. Its achievements also included the first rolling lock gates, the largest movable dam built in the 19th century, and the widest chamber in world history.
The Bonneville Dam, Columbia River Power and Navigation System consists of 55 major projects on Oregon's Columbia River and is said to be the largest hydroelectric system in the world.
The Columbia River forms part of the border between Washington and Oregon and flows inland through the only waterway that crosses the Cascade Mountains. To harness the energy of the ninth longest river in North America, engineers developed unique design and construction approaches to overcome problems caused by depth of water, current velocity, and an irregularly-shaped river bottom.