Engineering, Military. The U.S. Army's basic manual on what engineer troops should do in wartime defines five general tasks: mobility, countermobility, survivability, topography, and general engineering. The primary imperative is the offensive: movement. The obverse—impeding the movement of the enemy—is the engineer's second task. If the battlefield situation requires it, engineers must also provide expedient field fortifications, which will protect troops and equipment from enemy fire. Assisting the army in locating positions and understanding terrain is the engineers' fourth task. And finally, military engineers perform a variety of other duties, which change over time but are related to construction or destruction.

These five tasks, or “missions,” are relatively straightforward and have defined in a general sense the responsibilities of military engineers for centuries. But the relative importance of each task has changed during the more than 200‐year history of engineering in the U.S. Army.

Modern military engineering originated in seventeenth‐century France under the influence of Louis XIV's great engineer, Marshal Vauban. French military engineering had a particularly strong influence on the development of engineering in the American Army. As Gen. George Washington attempted to cobble together something approaching a respectable eighteenth‐century standing army, he included on his staff a chief engineer and two assistants. Because Washington could not find Americans formally trained in military engineering, he recruited foreign, mostly French, professional military engineers.

The hallmarks of French engineers in the eighteenth century were the great bastioned fortifications and the elaborate sieges required to capture them. In the primitive colonial environment, engineers had few opportunities for such sophisticated military engineering, but Continental army engineers made important contributions to American victory in the Revolutionary War. They mapped terrain, designed field fortifications such as those at Saratoga, and cleared roads until they achieved preeminence in the final battle of the war. At the Battle of Yorktown (1781), the American and French forces conducted a classic siege of the British positions and by their success ensured the independence of the American colonies.

For two decades after the Revolution, the U.S. Army Corps of Engineers existed sporadically, for awhile in a union with the artillery. The threat of war with European powers helped revive it in 1802 when President Thomas Jefferson and Congress reestablished the Corps at West Point, New York, where it would also “constitute a military academy” training especially military engineers. Until 1866, the Corps of Engineers ran the U.S. Military Academy and made it the first American college with a curriculum emphasizing engineering. The Corps modeled the academy on the Ecole Polytechnique and subscribed to the French view that a mathematically inclined, technical education best equipped young men to be army officers.

The Corps' French roots were demonstrated in its major activity in the early nineteenth century—designing and building brick and masonry seacoast fortifications. In a peculiarly American development born of the scarcity of native professional civilian engineers, the Corps of Engineers also became involved after 1824 in internal improvements on the rivers and harbors of the new nation. In another peculiarly American development, the army had two Corps of Engineers from 1818 to 1863: a Corps of Topographic Engineers, which devoted much attention to exploring and mapping the expanding country and to improving its rivers and harbors; and a Corps of Engineers, which concentrated on fortifications. Both groups were small and their bureaucratic domains sometimes overlapped. Both fought in the Mexican War, and both supported the Union military effort in 1861.

Although the Corps of Engineers was reunited in 1863 and expanded during the Civil War, most engineer troops, like those in the rest of the Union army, were volunteers. As in other wars, engineers mapped the theaters of operations and built bridges, but changing technology lent new urgency to some of their tasks. As rifling and breechloading increased the destructiveness of weapons, soldiers often improvised field fortifications. The war brought some grand sieges, which had been so much a part of the engineer tradition, but with ominous new dimensions. In the Confederate capture of Fort Sumter and the Union siege of Fort Pulaski, the new artillery rapidly demolished the carefully designed battlements. These setbacks did not deter classically trained engineers, both during the war and after, from promoting the construction of more seacoast fortifications, which they attempted to protect from the growing threat of more powerful artillery. Other sieges, like the one at Petersburg, presaged the trench warfare of the future; but Union engineers, like their peers in Europe, did not fully apprehend that new direction.

When the United States entered World War I, the great trench systems on the western front—the improvised and then improved field fortifications to protect soldiers from artillery and machine guns—were already in place. American engineers fought as infantry in the Allied assaults on the German lines and built bridges under fire, but the bulk of their work supported the enormous logistical effort required to supply the huge forces in northern France. The first engineers to France built railroads. They were followed by engineers who built roads, ports, and depots, and harvested lumber, their basic construction material. World War I made clear that engineers were critical not only in the front lines of combat but also behind those lines, where the huge logistical apparatus to support the insatiable appetites of modern industrialized warfare would require construction of all types.

On the eve of World War II, engineers could anticipate some of the growing combat and construction requirements of warfare. After the defensive deadlock of World War I, armies developed new tactics and new equipment, which emphasized movement and speed. Armored and mechanized engineer units had to keep up with the rapid movement of forces as the U.S. Army emulated the blitzkrieg warfare of the Germans. Engineers had to build bridges quickly, and these bridges had to be strong enough to carry heavy tanks. Specially equipped aviation engineer units trained to build front‐line airfields quickly. No longer would combat be static and circumscribed.

Behind the front lines, the new pace of warfare and the new technology increased the demand for engineers. Dozens of highly specialized units rehabilitated ports, built petroleum pipelines, repaired and maintained equipment, supplied parts, produced highly sophisticated maps and charts, and performed a wide variety of other tasks required by the most technologically advanced army of its day. Although promoting the mobility of American forces and impeding the mobility of their enemies became the engineers' primary tasks in World War II, support for the huge military infrastructure that made that mobility possible also placed great demands on them.

Engineers had always built the military infrastructure in combat theaters, but World War II brought new responsibility for constructing the facilities required at home to mobilize and deploy American armies. Before the war, most of this task belonged to the Quartermaster Corps, but the heavy demands of wartime mobilization led the army to transfer this mission to the Corps of Engineers. The Corps had also constructed coastal defenses and kept available a large, experienced civilian workforce, which was devoted in peacetime to navigation improvements and flood control construction programs. Now this combined military and civilian group was in charge of all army and Army Air Force construction. Besides designing and supervising the construction of the Pentagon and hundreds of mobilization facilities such as barracks, ammunition plants, and airfields, the engineers built the technologically sophisticated structures needed in the Manhattan project to develop the atomic bomb. World War II found military engineers working around the world to perform the largest array of missions in their history.

Within five years of demobilization in 1945, engineers were fighting another war with much the same tactics and equipment used in World War II. Until the military stalemate that led to de facto peace in Korea, engineers honed their traditional skills.

A little more than a decade later, the engineers, like the rest of the U.S. Army, confronted in the Vietnam War a conflict that was not traditional and not entirely tractable to the techniques of the two previous wars. Although the engineers built hundreds of miles of highways in South Vietnam and an elaborate logistical network that expanded beyond that typical in World War II, they struggled to best an elusive enemy that used guerrilla warfare. Adapting to the new tactics, engineers cleared landing zones for the newly important helicopters and cleared jungle from roadsides using massive Rome plows. Ultimately, however, their efforts accomplished little, as American troops were withdrawn from a war that bitterly divided the nation.

At home, the engineer role in prosecuting the Cold War against the Soviet Union was more successful. After the separation of the air force from the army in 1947, the Corps of Engineers remained the primary construction agency for both services. Besides routine construction for the army, the engineers built the sophisticated facilities required by the air forces' strategic missions—airfields for heavy bombers, launch facilities for intercontinental ballistic missiles, and radar installations. The Corps of Engineers also built many of the facilities for the National Aeronautics and Space Administration. The Cold War kept the engineers busier with peacetime military construction than ever before in their history.

The last conflicts of the Cold War, or perhaps the first war of the post–Cold War era in the case of the Persian Gulf War, brought the engineers like the rest of army back to their metier. Using a new generation of equipment and weapons developed during the Reagan defense buildup, the engineers assisted the Allied Coalition army in launching an air‐ground blitzkrieg in the deserts of the Middle East. In a reassuring victory, which demonstrated that America could still fight a conventional war against conventional foes, the engineers maintained a secure place in an army that still needed massive logistical support and the apparatus that would allow its heavy equipment to move rapidly despite the vagaries of terrain. Though the end of the Cold War and the reduced size of the armed services lessens the need for engineer construction in the United States and abroad today, doctrine assures, as it has done since the Revolution, that engineers will have a place in the army of the future.
[See also Academies, Service: U.S. Military Academy; Education, Military.]

Bibliography

William B. Parsons , American Engineers in France, 1920.
Emanuel R. Lewis , Fortifications of the United States: An Introductory History, 1970.
Frank N. Schubert , Vanguard of Expansion: Army Engineers in the Exploration of the Trans‐Mississippi West, 1980.
Paul K. Walker , Engineers of Independence: A Documentary History of the Army Engineers in the American Revolution, 1981.
Dale Floyd, ed., “Dear Friends at Home”: The Letters and Diary of Thomas James Owen, Fiftieth New York Volunteer Engineer Regiment, During the Civil War, 1985.
Janice Holt Giles , Damned Engineers, 1985.
Frank N. Schubert, ed., The Nation Builders: A Sesquicentennial History of the Corps of Topographical Engineers, 1838–1863, 1988.
Barry W. Fowle, ed., Builders and Fighters: U.S. Army Engineers in World War II, 1992.
Adrian Traas , From the Golden Gate to Mexico City: The U.S. Army Topographical Engineers in the Mexican War, 1846–1848, 1993.

William C. Baldwin