Civil War Earthworks

Civil War Earthworks. "Where they are compelled by nature ... to resort to it". During the Civil War, armies of both sides built earthwork fortifications of varying sizes and shapes. The star fort was one of the most difficult types to construct. Although the design afforded the defenders the potential to fire into an attacking enemy's flanks, Dennis Hart Mahan, Professor of Military and Civil Engineering at West Point and the author of A Treatise on Field Fortification first published in 1836, deemed it to be generally not a viable option. Mahan believed that in addition to "dead spaces", areas below the parapet that could not be covered by the fort's artillery, the amount of "time and labor required to throw up such a work" made the design impractical. He thought that the design should be used only "in cases where they are compelled by the nature of the site to resort to it."

Union Gen. Robert H. Milroy, who graduated first in his class at Norwich University in 1843 and received three degrees including master of military science, believed that the nature of the terrain at this site was suitable for a star fort. The soldiers who constructed it used the excavated soil from the ditch at the base of the fort and rifle pits that encircled it to build the parapet. Additionally, other materials, including trees and stones, were brought to the site to help build up the fort's outer wall. Although Milroy might have believed this type of construction to be "the most useful and safest kind," it did not save his army from defeat at the Second Battle of Winchester.

(captions) , (left illustration) Earthwork fortification under construction - Courtesy Library of Congress

(middle illustration) Dennis H. Mahan - Courtesy U.S. Military Academy Museum

(right illustration) Both Union and Confederate commanders, many of whom had been Dennis Hart Mahan's students at West Point, used his Treatise on Field Fortifications as a guide for constructing works such as these star forts.