In addition to the challenge of documenting war, war itself involved several problems of representation. O'Sullivan would have been as much concerned with reality and representation as a person living through the war as he was as a photographer. Trachtenberg points out that it was difficult to say just what the war was, fratricide, rebellion, a holy crusade, a battle between two nations or over slavery.18 Similarly, Timothy Sweet, quoting Emerson, shows how the issue of representation was central to the war:

The American Civil War arose from a crisis in political representation. Emerson, in his "Speech on Affairs in Kansas"(1856), describes the breakdown of all structures of representation, including language itself, during the decade before the war: "language has lost its meaning in the universal cant. Representative Government is misrepresentative; Union is a conspiracy against the Northern States which the Northern States are to have the privilege of paying for; the adding of Cuba and Central America to the slave marts is enlarging the area of Freedom. Manifest Destiny, Democracy, Freedom, fine names for an ugly thing."19

There was a crisis in political representation because representations of meaning, and thus meaning itself, could not be agreed upon. The same idea or event meant different things to the North and the South. And this difference in perspective was so acute that it meant that they weren't in fact looking at or talking about the same thing, but two different things. This duplication of things was the breakdown of representation.

Furthermore, Sweet explains how war is a process by which, according to Elaine Scarry, politics and ideology are represented by violence, specifically wounds, when questions of politics and ideology cannot be settled through the use of traditional representative structures such as language:

Violence to the body of the soldier, 'the main purpose and outcome of war,' is made to substantiate the ideology of the victor by means of a complex semiotic process....wounds come to be perceived in separation from bodies, as objects in themselves. As material facts, wounds are so palpable that they make the ideological outcome of a war 'seem real until there is time for the issues to be universally acted on and in this way made real'.20

Intrinsic to the very substance and purpose of war is a process of representation by which the physical and visual come to stand for the conceptual. Wounds and violence are structures of representation like language or images. We can only guess to what extent O'Sullivan would have been aware of this. Surely, he knew of Gardner's use of photographs, many his own, in his Photographic Sketchbook of the Civil War to promote a historical reading of the war that vindicated the Union. This would have made plain the potential of photographs to send a political message, and even illustrated the role photographs could play in representing wounds and death as "objects in themselves". This is especially true of Gardner's use of O'Sullivan's own "Harvest of Death".

Gardener supplements this and like images with text that unites them directly with an ideological position. He associates the corpses he identifies as confederates with the word "devilish!" adding that "the distorted dead recall the ancient legends of men torn in pieces by the savage wantonness of fiends."21 In this association, the bloated bodies of the dead confederates are equated with evil, though clumsily, as it also equates the union soldiers with savage fiends. On the following page, Gardner associates the union dead in "Field Where General Reynolds Fell" with monuments or with the suffering and immortality of martyred saints:

Some of the dead presented an aspect which showed that they had suffered severely just previous to dissolution, but these were few in number compared with those who wore a calm and resigned expression, as though they had passed away in the act of prayer. Others had a smile on their faces, and looked as if they were in the act of speaking. Some lay stretched on their backs, as if friendly hands had prepared them for burial. Some were still resting on one knee, their hands were grasping their muskets. In some instances the cartridge remained between the teeth, or the musket was held in one hand,, and the other was uplifted as though to ward a blow, or appealing to heaven. The faces of all were pale, as though cut in marble, and as the wind swept across the battle-field it waved the hair, and gave the bodies such an appearance of life that a spectator could hardly help thinking they were about to rise to continue the flight. 22

Gardner objectifies the dead bodies, even itemizing them into hands, faces, backs, knees, teeth, and hair. He then assigns them ideological meaning. It is impossible to know to what extent O'Sullivan contributed to Gardner's book, if he just took the photographs, assigned them their titles, or even helped to write the extended captions. An extended discussion of this question follows in the next section. Suffice it to say at this point, that not only as photographer, but as a photographer living through and documenting the Civil War, O'Sullivan and any other field photographer as dedicated to his project, was inundated with questions of reality and representation. Both the history of the war and the photography that documents it suggest the lesson of relative truth or reality; that the truth or reality of war depends upon the perspective from which it is considered or viewed.