The American Civil War saw a massive development in the use of field fortifications. Often considered the first modern war, scenes during many of the campaigns and battles of the conflict foreshadowed the shape of things to come in the trenches of the First World War of 1914-18. Early in the Civil War during actions such as Big Bethel, First Manassas (Bull Run), and the Seven Days' Battles, soldiers were required to dig simple defensive rifle trenches or pits in order to hold their ground. However, as a result of the increased practical application of lessons learned at the US Military Academy in the antebellum years, and the deadly impact of rifled infantry weapons and artillery, both Northern and Southern armies began to adopt and develop a far more sophisticated system of field fortifications as the Civil War unfolded. The unsuccessful Union assault on the Confederate field positions on Marye's Heights at Fredericksburg in December 1862 was early evidence of the employment and impact of semi-fortified lines. Union General Joseph Hooker's withdrawal from Fredericksburg towards the Rappahannock was subsequently covered by entrenched positions. In a concentrated position fronting the river, the pioneer brigade of the Army of the Potomac, commanded by General Gouverneur I<. Warren, threw up five miles of formidable entrenchments in less than 48 hours. Accordingly, Confederate artillery commander E. F. Alexander commented, "Our engineers were amazed at the strength and completeness of the enemy's entrenchments. Impenetrable abatis covered the entire front, and the crest everywhere carried head-logs under which the men could fire as through loopholes. In the rear, separate structures were provided for officers, with protected out-looks, where they could see and direct without exposure."
At Chancellorsville in May 1863, Hooker further entrenched much of his army behind parapets and log breastworks supported by abatis. At some points his troops threw up a triple line of entrenchments. Gettysburg saw the construction of makeshift fieldworks from rocks or split rail fence, plus rifle trenches, as appropriate to the terrain, along nearly the entire length of each opposing line of battle. Those of the Union army were particularly effective on Culp's Hill, Cemetery Hill, the Angle, and the Round Tops, when the Confederates made their valiant attacks on the second and third days of the battle.
Soldiers standing at the gate of Fort Slemmer, one of the enclosed forts constructed to the north of Washington, DC. Note the wide wooden ramp that gave access across a deep ditch.The siege gun in the rear stands on a wooden barbette carnage. (Library of Congress B8I 1-2318)
By 1864, the trend towards a more elaborate system of fortification had evolved into the more sophisticated fieldworks used at Spotsylvania Court House and Cold Harbor, in Virginia. Similarly, the larger field works and fortifications surrounding Washington, DC and Richmond, Virginia were redesigned and rebuilt several times. By 1865 they approached a standard of physical adaptation little short of permanent fortifications. Indeed, in a report dated October 20, 1864 Major Nathaniel Michler, Corps of Engineers, US Army, summed up the changing face of warfare: "The new era in field-works has so changed their character as in fact to render them almost as strong as permanent ones, and the facility with which new and successive lines of works can be constructed (so well proven throughout the whole campaign just terminated) renders it almost useless to attempt a regular siege. The open assault of works is attended with immense loss of life, but at the same time during the slow operations of the siege the sharpshooter so effectually does his work as to produce a large bill of mortality."
The nine-month siege of Petersburg, which is the longest siege in the history of American warfare and involved nearly 150,000 soldiers in both Union and Confederate armies, saw some of the most sustained fighting and extensive building of fortifications of the Civil War. The Petersburg lines witnessed the further development of redoubts, lunettes, and redans, as well as bomb-proof shelters and powder magazines, covered ways, rifle trenches, and rifle pits. Mining was attempted by both armies, and resulted in the debacle of the Battle of the Crater on July 30, 1864. With the final collapse of the sparsely manned Petersburg lines on April 2, 1865, the Confederates evacuated their capital, and one week later the remains of the Army of Northern Virginia surrendered at Appomattox Court House. The Civil War was over, and the face of warfare had changed forever.
The subject of this volume is the role of land and field fortifications in the eastern and western campaigns of the Civil War between 1861 and 1865. The part they played in the Mississippi and Tennessee river valleys, and along the Atlantic coast and in the Culf of Mexico, will be dealt with in future proposed volumes in the Fortress series.
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