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.

[196] first maxim dictating that it was better to dig dirt than to stand up and be shot at, and the second quickly pointed the way to make dirt digging effective. Great necessity and the stern experience of war drove erroneous notions from the heads of the combatants, and before the conflict had progressed far, we find both armies digging trenches without orders, whether in the presence of the enemy or not.

One of the historians of the war has stated that they waited neither for orders, deployment of skirmishers, nor even for formation of lines. The standing rule, adopted by common consent without a dissenting voice, was that they should proceed with this work without waiting for instructions. It mattered not that their lines might soon be moved. A little labor and effort on the soldiers' part at the opportune time often saved a life later.

It was the good common sense of the troops that led them to understand the value of even slight protection. The high intelligence of the individual American soldier made it a simple matter for him to grasp this fundamental truth of his own accord. He did not need to be educated to it by his officers; he knew it by instinct as soon as the enemy began firing at him. Nor was the initiative in the matter of seeking both natural and artificial protection caused by his knowledge of the art of war. Certain features of the art came to him instinctively, and this was one of them.

The Confederates made great use of earthworks, and by their aid were able to hold the Federals, in superior numbers, at half-rifle-shot distance on many hard-fought fields. On many occasions they extemporized protection and dug themselves into rifle-pits, hid their artillery in gun-pits and behind epaulments on the flanks of their infantry lines, and thus made their positions impregnable.

The rapidity with which adequate protection from rifle fire could be obtained by the use of bayonets, tin cups, knives, and other parts of the equipment which the soldier always had