USACE

, colors =
, anniversaries = 16 June (Organization Day)
, battles =
, battles_label = Wars
, website =
, commander1 = LTG Scott A. Spellmon
, commander1_label = Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers
, commander2 = MGbr>Richard J. Heitkamp
, commander2_label = Deputy Chief of Engineers and Deputy Commanding General
, commander3 = MG
Kimberly M. Colloton
, commander3_label = Deputy Commanding General for Military and International Operations
, commander4 = MGbr>William H. Graham
, commander4_label = Deputy Commanding General for Civil and Emergency Operations
, commander5 = COLbr>James J. Handura
, commander5_label = Chief of Staff for the U.S. Army Corps of Engineers Headquarters
, commander6 = CSMbr>Patrickson Toussaint
, commander6_label = Command Sergeant Major, U.S. Army Corps of Engineers
, identification_symbol =
, identification_symbol_label = Flag
, identification_symbol_2 =
, identification_symbol_2_label = Logo
, identification_symbol_3 =
, identification_symbol_3_label = Coat of arms
, identification_symbol_5 =
, identification_symbol_5_label = Engineer Regimental insignia
, identification_symbol_6 = USACE
, identification_symbol_6_label = Abbreviation

The United States Army Corps of Engineers (USACE) is an engineer formation of the United States Army that has three primary mission areas: Engineer Regiment, military construction, and civil works. The day-to-day activities of the three mission areas are administered by a lieutenant general known as the commanding general/chief of engineers. The chief of engineers commands the Engineer Regiment, comprising combat engineer, rescue, construction, dive, and other specialty units, and answers directly to the Chief of Staff of the Army. Combat engineers, sometimes called sappers, form an integral part of the Army's combined arms team and are found in all Army service components: Regular Army, National Guard, and Army Reserve. Their duties are to breach obstacles; construct fighting positions, fixed/floating bridges, and obstacles and defensive positions; place and detonate explosives; conduct route clearance operations; emplace and detect landmines; and fight as provisional infantry when required. For the military construction mission, the commanding general is directed and supervised by the Assistant Secretary of the Army for installations, environment, and energy, whom the President appoints and the Senate confirms. Military construction relates to construction on military bases and worldwide installations.

Continental Congress authority for a "Chief Engineer for the Army" dates from 16 June 1775. Congress authorized a corps of engineers for the United States on 11 March 1779. The Corps as it is known today came into being on 16 March 1802, when the president was authorized to "organize and establish a Corps of Engineers ... that the said Corps ... shall be stationed at West Point in the State of New York and shall constitute a Military Academy." A Corps of Topographical Engineers, authorized on 4 July 1838, merged with the Corps of Engineers in March 1863.

For the civil works mission the commanding general is directed and supervised by the Assistant Secretary of the Army, also appointed by the President and confirmed by the Senate. Army civil works consists of three congressionally authorized business lines: navigation, flood and storm damage protection, and aquatic ecosystem restoration. Civil works is also tasked with administering the Clean Water Act Section 404 program, recreation, hydropower, and water supply at USACE flood control reservoirs, and environmental infrastructure. The civil works staff oversee construction, operation, and maintenance of dams, canals and flood protection in the U.S., as well as a wide range of public works throughout the world. USACE has 37,000 civilian and military personnel, making it one of the world's largest public engineering, design, and construction management agencies. Some of its dams, reservoirs, and flood control projects also serve as public outdoor recreation facilities. Its hydroelectric projects provide 24% of U.S. hydropower capacity. It is headquartered in Washington, D.C. and has a budget of $7.8 billion (FY2021).

The corps's mission is to "deliver vital public and military engineering services; partnering in peace and war to strengthen our nation's security, energize the economy and reduce risks from disasters."

Its most visible civil works missions include:

* Planning, designing, building, and operating locks and dams. Other civil engineering projects include flood control, beach nourishment, and dredging for waterway navigation.
* Design and construction of flood protection systems through various federal mandates.
* Design and construction management of military facilities for the Army, Air Force, Army Reserve, and Air Force Reserve as well as other Department of Defense and federal government agencies.
* Environmental regulation and ecosystem restoration.

History

Early history

The history of United States Army Corps of Engineers can be traced back to the revolutionary era. On 16 June 1775, the Continental Congress organized an army which staff included a chief engineer and two assistants.The U.S. Army Corps of Engineers: A Brief History
U.S. Army Corps of Engineers Headquarters. Colonel Richard Gridley became General George Washington's first chief engineer. One of his first tasks was to build fortifications near Boston at Bunker Hill. The Continental Congress recognized the need for engineers trained in military fortifications and asked the government of King Louis XVI of France for assistance. Many of the early engineers in the Continental Army were former French officers.

Louis Lebègue Duportail, a lieutenant colonel in the French Royal Corps of Engineers, was secretly sent to North America in March 1777 to serve in George Washington's Continental Army. In July 1777 he was appointed colonel and commander of all engineers in the Continental Army and, on 17 November 1777, he was promoted to brigadier general. When the Continental Congress created a separate Corps of Engineers in May 1779, Duportail was appointed as its commander. In late 1781 he directed the construction of the allied U.S.-French siege works at the Battle of Yorktown.

On 26 February 1783, the Corps was disbanded. It was re-established during the Presidency of George Washington.

From 1794 to 1802, the engineers were combined with the artillery as the Corps of Artillerists and Engineers.

The Corps of Engineers, as it is known today, was established on 16 March 1802, when President Thomas Jefferson signed the Military Peace Establishment Act, whose aim was to "organize and establish a Corps of Engineers ... that the said Corps ... shall be stationed at West Point in the State of New York and shall constitute a military academy." Until 1866, the superintendent of the United States Military Academy was always an Engineer Officer.

The General Survey Act of 1824 authorized the use of Army engineers to survey road and canal routes for the growing nation. That same year, Congress passed an "Act to Improve the Navigation of the Ohio and Mississippi Rivers" and to remove sand bars on the Ohio and "planters, sawyers, or snags" (trees fixed in the riverbed) on the Mississippi, for which the Corps of Engineers was identified as the responsible agency.

Formerly separate units

Separately authorized on 4 July 1838, the Corps of Topographical Engineers consisted only of officers and was used for mapping and the design and construction of federal civil works and other coastal fortifications and navigational routes. It was merged with the Corps of Engineers on 31 March 1863, at which point the Corps of Engineers also assumed the Lakes Survey District mission for the Great Lakes.

In 1841, Congress created the Lake Survey. The survey, based in Detroit, Michigan, was charged with conducting a hydrographical survey of the Northern and Northwestern lakes and preparing and publishing nautical charts and other navigation aids. The Lake Survey published its first charts in 1852.

In the mid-19th century, Corps of Engineers' officers ran Lighthouse Districts in tandem with U.S. Naval officers.

Civil War

The Army Corps of Engineers played a significant role in the American Civil War. Many of the men who would serve in the top leadership in this organization were West Point graduates. Several rose to military fame and power during the Civil War. Some examples include Union generals George McClellan, Henry Halleck, and George Meade; and Confederate generals Robert E. Lee, Joseph Johnston, and P.G.T. Beauregard. The versatility of officers in the Army Corps of Engineers contributed to the success of numerous missions throughout the Civil War. They were responsible for building pontoon and railroad bridges, forts and batteries, destroying enemy supply lines (including railroads), and constructing roads for the movement of troops and supplies. Both sides recognized the critical work of engineers. On 6 March 1861, once the South had seceded from the Union, its legislature passed an act to create a Confederate Corps of Engineers.First Lieutenant Shaun Martin, "Confederate Engineers in the American Civil War," ''Engineer: The Professional Bulletin for Army Engineers''. Technology Industry. U.S. Civil War Center

The South was initially at a disadvantage in engineering expertise; of the initial 65 cadets who resigned from West Point to accept positions with the Confederate Army, only seven were placed in the Corps of Engineers. The Confederate Congress passed legislation that authorized a company of engineers for every division in the field; by 1865, the CSA had more engineer officers serving in the field of action than the Union Army.

One of the main projects for the Army Corps of Engineers was constructing railroads and bridges. Union forces took advantage of such Confederate infrastructure because railroads and bridges provided access to resources and industry. The Confederate engineers outperformed the Union Army in building fortifications that were used both offensively and defensively, along with trenches that made them harder to penetrate. This method of building trenches was known as the zigzag pattern.

20th century

The National Defense Act of 1916 authorized a reserve corps in the Army, and the Engineer Officers' Reserve Corps and the Engineer Enlisted Reserve Corps became one of the branches. Some of these personnel were called into active service for World War I.

From the beginning, many politicians wanted the Corps of Engineers to contribute to both military construction and civil works. Assigned the military construction mission on 1 December 1941, after the Quartermaster Department struggled with the expanding mission, the Corps built facilities at home and abroad to support the U.S. Army and Air Force. During World War II the USACE program expanded to more than 27,000 military and industrial projects in a $15.3 billion mobilization effort. Included were aircraft, tank assembly, and ammunition plants; camps for 5.3 million soldiers; depots, ports, and hospitals; and the rapid construction of such landmark projects such as the Manhattan Project at Los Alamos, Hanford and Oak Ridge among other places, and the Pentagon, the Department of Defense headquarters across the Potomac from Washington, DC.

In civilian projects, the Corps of Engineers became the lead federal navigation and flood control agency. Congress significantly expanded its civil works activities, becoming a major provider of hydroelectric energy and the country's leading provider of recreation, Its role in responding to natural disasters also grew dramatically, especially following the devastating Mississippi Flood of 1927. In the late 1960s, the agency became a leading environmental preservation and restoration agency.

In 1944, specially trained army combat engineers were assigned to blow up underwater obstacles and clear defended ports during the invasion of Normandy. During World War II, the Army Corps of Engineers in the European Theater of Operations was responsible for building numerous bridges, including the first and longest floating tactical bridge across the Rhine at Remagen, and building or maintaining roads vital to the Allied advance across Europe into the heart of Germany. In the Pacific theater, the "Pioneer troops" were formed, a hand-selected unit of volunteer Army combat engineers trained in jungle warfare, knife fighting, and unarmed jujitsu (hand-to-hand combat) techniques.Whittaker, Wayne, "Tough Guys", ''Popular Mechanics'', February 1943, Vol. 79 No. 2, pp. 41, 44-45 Working in camouflage, the Pioneers cleared jungle, prepared routes of advance and established bridgeheads for the infantry, as well as demolishing enemy installations.

Five commanding generals (chiefs of staff after the 1903 reorganization) of the United States Army held engineer commissions early in their careers. All transferred to other branches before being promoted to the top position. They were Alexander Macomb, George B. McClellan, Henry W. Halleck, Douglas MacArthur, and Maxwell D. Taylor.

Notable dates and projects

* The General Survey Act of 1824 authorized use of army engineers to survey roads and canals. The next month, an act to improve navigation on the Ohio and Mississippi rivers initiated the Corps of Engineers' permanent civil works construction mission. Although the 1824 act to improve the Mississippi and Ohio rivers is often called the first rivers and harbors legislation, the act passed in 1826 was the first to combine authorizations for both surveys and projects, thereby establishing a pattern that continues to the present day.
* Survey and construction of the National Road until Federal funds were withdrawn (1838)
* The tall Washington Monument, completed under the direction and command of Lieutenant Colonel Thomas Lincoln Casey, 1884
* Panama Canal, completed under supervision of Army Engineer officers, 1914
* Flood Control Act of 1936, completed in 1937
* Flood Control Act of 1941, which channelized the Los Angeles River and parts of the Santa Ana River
* USACE took over all real estate acquisition, construction, and maintenance for army facilities, 1941
* There was no road between Costa Rica and Panama until the Corps began one in 1941–1943. The concern was access to the Panama Canal during wartime.
* The Manhattan Project (1942–1946)
* Planning and construction of The Pentagon, completed in 1943 just 16 months after groundbreaking
* Comprehensive Everglades Restoration Plan, first authorized by congress in 1948
* USACE began construction support for NASA leading to major activities at the Manned Spacecraft Center and Kennedy Space Center, 1961
* King Khalid Military City 1973–1987.
* The Water Resources Development Act of 1986 (WRDA 86) brought major change in financing by requiring non-federal contributions toward most federal water resource projects
* Cross Florida Barge Canal
* Tennessee-Tombigbee Waterway
Occasional civil disasters, including the Great Mississippi Flood of 1927, resulted in greater responsibilities for the Corps of Engineers. The aftermath of Hurricane Katrina in New Orleans