United States Army Corps of Engineers in the context of "Combat engineer"

The Pentagon is the headquarters building of the United States Department of Defense, in Arlington County, Virginia, across the Potomac River from Washington, D.C. The building was constructed on an accelerated schedule during World War II. As a symbol of the U.S. military, the phrase The Pentagon is often used as a metonym for the Department of Defense and its leadership.

The building was designed by American architect George Bergstrom and built by contractor John McShain. Ground was broken on 11 September 1941, and the building was dedicated on 15 January 1943. General Brehon Somervell provided the major impetus to gain Congressional approval for the project. Colonel Leslie Groves was responsible for overseeing the project for the U.S. Army Corps of Engineers, which supervised it.

Brehon Burke Somervell (9 May 1892 – 13 February 1955) was a general in the United States Army and Commanding General of the Army Service Forces in World War II. As such he was responsible for the U.S. Army's logistics. Following his death, The Washington Post lauded him as "one of the ablest officers the United States Army has produced".

Somervell graduated near the top of his United States Military Academy class of 1914 and was commissioned in the United States Army Corps of Engineers. During World War I he served with the Pancho Villa Expedition in Mexico and the American Expeditionary Force in France in logistical posts. He was also decorated for gallantry in the Meuse-Argonne Offensive.

Leslie Richard Groves Jr. (17 August 1896 – 13 July 1970) was a United States Army Corps of Engineers officer who oversaw the construction of the Pentagon and directed the Manhattan Project, a top secret research project that developed the atomic bomb during World War II.

The son of a U.S. Army chaplain, Groves lived at various Army posts during his childhood. In 1918, he graduated fourth in his class at the United States Military Academy at West Point and was commissioned into the United States Army Corps of Engineers. In 1929, he went to Nicaragua as part of an expedition to conduct a survey for the Inter-Oceanic Nicaragua Canal. Following the 1931 Nicaraguan earthquake, Groves took over Managua's water supply system, for which he was awarded the Nicaraguan Presidential Medal of Merit. He attended the Command and General Staff School at Fort Leavenworth, Kansas, in 1935 and 1936, and the Army War College in 1938 and 1939, after which he was posted to the War Department General Staff. Groves developed "a reputation as a doer, a driver, and a stickler for duty". In 1940 he became special assistant for construction to the Quartermaster General, tasked with inspecting construction sites and checking on their progress. In August 1941, he was appointed to create the gigantic office complex for the War Department's 40,000 staff that would ultimately become the Pentagon.

Panama, officially the Republic of Panama, is a country located at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and the Pacific Ocean to the south. Its capital and largest city is Panama City, whose metropolitan area is home to nearly half of the country's over 4 million inhabitants.

Before the arrival of Spanish colonists in the 16th century, Panama was inhabited by a number of different indigenous tribes. It broke away from Spain in 1821 and joined the Republic of Gran Colombia, a union of Nueva Granada, Ecuador, and Venezuela. After Gran Colombia dissolved in 1831, Panama and Nueva Granada eventually became the Republic of Colombia. With the backing of the United States, Panama seceded from Colombia in 1903, allowing the construction of the Panama Canal to be completed by the United States Army Corps of Engineers between 1904 and 1914. The 1977 Torrijos–Carter Treaties agreed to transfer the canal from the United States to Panama on December 31, 1999. The surrounding territory was returned first, in 1979.

The Illinois Waterway system consists of 336 miles (541 km) of navigable water from the mouth of the Calumet River at Chicago to the mouth of the Illinois River at Grafton, Illinois. Based primarily on the Illinois River, it is a system of rivers, lakes, and canals that provide a commercial shipping connection from the Great Lakes to the Gulf of Mexico via the Illinois and Mississippi rivers.

The Illinois and Michigan Canal (I&M) opened in 1848. In 1900, the Chicago Sanitary and Ship Canal replaced the I&M and reversed the flow of the Chicago River so it no longer flowed into Lake Michigan. The United States Army Corps of Engineers maintains a 9-foot-deep (2.7 m) navigation channel in the waterway. The waterway's complex northern section is referred to in various contexts for study and management as the Chicago Area Waterway System (CAWS).

The Army Map Service (AMS) was the military cartographic agency of the United States Department of Defense from 1941 to 1968, subordinated to the United States Army Corps of Engineers. On September 1, 1968, the AMS was redesignated the U.S. Army Topographic Command (USATC) and continued as an independent organization until January 1, 1972, when it was merged into the new Defense Mapping Agency (DMA) and redesignated as the DMA Topographic Center (DMATC). On October 1, 1996, DMA was folded into the National Imagery and Mapping Agency (NIMA), which was redesignated as the National Geospatial-Intelligence Agency (NGA) in 2003.

The major task of the Army Map Service was the compilation, publication and distribution of military topographic maps and related products required by the Armed Forces of the United States. The AMS was also involved in the preparation of extraterrestrial maps of satellite and planetary bodies; the preparation of national intelligence studies; the establishment of world geodetic control networks by both satellite and conventional triangulation methods; and the logistic military planning of Corps of Engineer items. Another major responsibility of the AMS was to maintain the largest geodetic and topographic data libraries for the Department of Defense.

The Clean Water Act (CWA) is the primary federal law in the United States governing water pollution. Its objective is to restore and maintain the chemical, physical, and biological integrity of the nation's waters; recognizing the primary responsibilities of the states in addressing pollution and providing assistance to states to do so, including funding for publicly owned treatment works for the improvement of wastewater treatment; and maintaining the integrity of wetlands.

The Clean Water Act was one of the first and most influential modern environmental laws in the United States. Its laws and regulations are primarily administered by the U.S. Environmental Protection Agency (EPA) in coordination with state governments, though some of its provisions, such as those involving filling or dredging, are administered by the U.S. Army Corps of Engineers. Its implementing regulations are codified at 40 C.F.R. Subchapters D, N, and O (Parts 100–140, 401–471, and 501–503).

The Manhattan Project was a research and development program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. The Manhattan Project employed nearly 130,000 people at its peak and cost nearly US$2 billion (equivalent to about $28 billion in 2024).

From 1942 to 1946, the project was directed by Major General Leslie Groves of the U.S. Army Corps of Engineers. Nuclear physicist J. Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the bombs. The Army program was designated the Manhattan District, as its first headquarters were in Manhattan; the name gradually superseded the official codename, Development of Substitute Materials, for the entire project. The project absorbed its earlier British counterpart, Tube Alloys.

The chief of engineers is a principal United States Army staff officer at The Pentagon. The chief advises the Army on engineering matters, and serves as the Army's topographer and proponent for real estate and other related engineering programs. The chief of engineers is the senior service engineer for the Department of Defense, responsible for integrating all aspects of combat, general and geospatial engineering across the Joint Force.

The chief of engineers also commands the United States Army Corps of Engineers. As commander of the U.S. Army Corps of Engineers, the chief of engineers leads a major Army command that is the world's largest public engineering, design, and construction management agency. This office defines policy and guidance, and it plans direction for the organizations within the Corps. The chief of engineers is currently a lieutenant general billet but in the past has been held by field grade officers as low as major. Civilian oversight of the chief of engineers is provided by the assistant secretary of the Army for civil works.