The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 5: Forts and Artillery.
Francis Trevelyan Miller, Ed.

[216] placed. With only a light line of works, he was able to withstand the onslaughts of one of the best armies of the Confederacy and withdraw with all his trains and supplies, after inflicting a very large loss on the Southerners and sustaining a comparatively light one himself. Had the conditions been reversed, Hood's army would probably have done as well as Schofield's. They were all Americans of the same intrinsic quality. One force was behind breastworks, slight as they were, and the other was the assaulting party. Again, at Nashville, Thomas and Hood contended on equal terms behind their respective lines, but when Thomas became sufficiently strong he was able to drive Hood out of his works and then defeat him, as he did, on December 16, 1864.

The cost of assaults on entrenchments during all these late campaigns of the war was tremendous. The losses in Grant's army from the time he crossed the Rapidan until he reached the James — a little over a month — were nearly equal to the strength of the entire Confederate army opposing him at the outset. Again, at Petersburg, the attack cost the Union army, in killed and wounded, a number almost equal to the entire force of the foe actually opposed.

As for the profile, showing the strength of parapet of the works employed, there was no fixed rule, and the troops used arbitrary measures. Ten to fifteen feet of fairly solid earth generally sufficed to withstand the heaviest cannon, while a thickness of two feet and a low parapet would protect against rifle fire. If logs or other heavy timber were at hand, the thickness of the parapet could be correspondingly reduced. It was found that even a slight work, if held by strong rifle fire, always prevailed against the advancing force, unless the latter attacked in overwhelming numbers.

Of the stronger fortifications on each side, those exemplifying the best types were the defenses of Washington, of Richmond and Petersburg, of Vicksburg, Port Hudson, and New Orleans, and the works at Mobile, Fort Fisher, Fort Pulaski,