Army Corps of Engineers, U.S.

The Continental Congress in June 1775 organized what later became the U.S. Army Corps of Engineers (ACE) when it authorized an engineer and two assistants to prepare fortifications for the Battle of Bunker Hill. Engineers were further organized in 1779, but it was not until after the Revolutionary War that the Corps was permanently established, in 1802. Thus, the Army Corps of Engineers, located within the Department of Defense, is the nation's oldest water resource agency, dealing primarily with the construction and maintenance of navigable streams and harbors.

Nineteenth Century

The Corps contributed to both civilian and military constructions (e.g., lighthouses, coastal fortifications, and harbors) when national defense and commercial transportation were determined to be interdependent. Many historians claim that the greatest accomplishment of the early Corps was its work on forming a reliable transportation system within the expanding United States, via activities such as mapping navigation channels and building canals and harbors.

The General Survey Act (1824) authorized the Corps to formulate surveys for waterways that were of commercial or military importance, or were used for mail delivery. The Corps was assigned to improve navigation on the Ohio and Mississippi Rivers, and later on the Missouri River. The Corps' work on the interior transportation system of the country was a vital foundation for economic development and westward expansion.

Twentieth Century

The Corps' efforts to improve waterway navigation continued with the deepening of the Chesapeake and Delaware Canal (1926) that eventually became a part of the intercoastal waterway connecting waterbodies from Massachusetts to Florida and westward to the Rio Grande River. Construction and maintenance of canals, locks, and other structures continued, along with important surveys of the Great Lakes and Mississippi Delta. The principal national expenditure up to this time period was directed at levee construction.

Dam Regulations.

The country's water resources became a concern during the beginning of the century due to neglected waterways, increased hydropower demands, and additional western irrigation projects. Numerous dams were constructed when studies showed that hydroelectric power was an efficient use of water. However, it was also concluded that dams threatened waterway navigation. As a result, Congress delegated the Corps to regulate dam construction.

The U.S. Army Corps of Engineers continues to play a key role in maintaining navigation on the nation's major waterways. Here an ore carrier passes through the locks of Soo Locks, which connect Lake Superior and Lake Huron.
The U.S. Army Corps of Engineers continues to play a key role in maintaining navigation on the nation's major waterways. Here an ore carrier passes through the locks of Soo Locks, which connect Lake Superior and Lake Huron.

The Rivers and Harbors Acts (1890 and 1899) required that construction plans and specific dam sites be approved by the Corps, while the General Dam Act (1906) forced dam owners to construct, operate, and maintain their facilities in specific ways. During the 1930s, the Corps participated in three major hydroelectric projects: Passamaquoddy Tidal Power (Maine), Bonneville Dam (Columbia River), and Fort Peck Dam (Missouri River).

Flood Control Measures.

The failures of an uncoordinated levee system was recognized as early as 1879, when the Mississippi River Commission was created to undertake flood control planning on the lower Mississippi. Despite this Commission, the existing levee-based flood control system was proven to be inadequate when two major floods in 1912–1913 and another one in 1916 flooded the lower Mississippi River valley.

These floods caused significant economic damages and human suffering. Damages to property and commerce were quite costly. And these were recurring events. When over 16 million acres in the lower Mississippi River valley were flooded again in 1928, Congress passed flood control legislation and gave a role to the Corps in its implementation.

Floods continued to cause substantial damage, and, with severe flooding events on the Ohio River, Congress passed the 1936 Flood Control Act. Until this time, Congress had been hesitant to create a strong role for the federal government in floodplain management. This act declared flood control to be acceptable federal government activity and authorized more than two hundred construction projects. Under the act, both the Corps and the Department of Agriculture shared responsibility for these activities.

This legislation was a significant event in Corps history for two reasons. First, it authorized physical structures as the means to control floods, and these construction activities were historically the Corps' expertise. Second, it was the first significant federal use of the cost-benefit ratio as a decisionmaking criterion. The act includes the famous provision that "the benefits to whomsoever they accrue exceed the costs" and launched the use of cost-benefit analysis for water projects. This economically based decisionmaking criterion spurred the Corps' involvement in water resources planning. The Flood Control Act (1944) allowed the Corps to build multiple-purpose reservoirs, mainly for irrigation, navigation, water supply, hydropower, and recreation.

Electrical Output.

After 1945, additional multipurpose hydroelectric projects were built on the Columbia and Snake Rivers in the Pacific Northwest, and the Missouri and the Arkansas Rivers. By 1975, Corps projects were producing 27 percent of the total U.S. hydropower and 4.4 percent of all electrical energy output.


The Corps is an organization that has historically built water infrastructure. The Corps' current regulatory mission is a natural result of its historical mission and society's changing needs. Environmental considerations are becoming increasingly important to the Corps' activities. Public controversies over structural projects have pressured the Corps to account for the environmental impacts of its construction activities and to widen its consideration of nonstructural approaches to solve water problems.

The Corps continues to be involved in ongoing controversies related to its activities, and these conflicts are indicative of the evolution that water planning and management is undergoing. The Corps has historically played an important role in water management, and will continue to do so as its mission and mandates change.

SEE ALSO Balancing Diverse Interests ; Bureau of Reclamation, U.S. ; Canals ; Cost-Benefit Analysis ; Dams ; Floodplain Management ; Hydroelectric Power ; Infrastructure, Water-Supply ; Planning and Management, History of Water Resources ; Ports and Harbors ; River Basin Planning ; Transportation ; White, Gilbert .

William Arthur Atkins

Faye Anderson


National Research Council. New Directions in Water Resources Planning for the U.S. Army Corps of Engineers. Washington, D.C.: National Academy Press, 1999.

Shallat, Todd, and William H. Goetzmann, eds. Structures in the Stream: Water, Science, and the Rise of the U.S. Army Corps of Engineers. Austin: University of Texas Press, 1994.

Internet Resources

ACE Institute for Water Resources. <> .

Brief History. Office of History, U.S. Army Corps of Engineers. <> .


In 1802, Albert Gallatin delivered a Congressional report outlining his plan to improve the U.S. transportation system. Called the Gallatin Report (1808), it listed improvements to roads and canals connecting northern and southern states, northern states to the Great Lakes, and eastern states with western areas.

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