The Killer Angels by Michael Shaara

Longstreet sat on a rail fence, hugging his chest with both arms. He suspended thinking; his mind was a bloody vacancy, like a room in which there has been a butchering. He tried once formally to pray, but there was no one there and no words came, and over and over he said to himself, Heavenly Father, Heavenly Father. He watched the battle dissolve to nightmare: the neat military lines beginning to come apart as they crossed the road and no order beyond that but black struggling clots and a few flags in the smoke, tilting like sails above a white sea, going down one by one. A shell burst near Longstreet and he felt the hot brutal breath, and then the sounds of battle were softer, the smoke began to blanket the field.

But there was still a few flags moving toward the top of the hill. Longstreet put glasses to his eyes, saw ghost figures stumbling in white smoke, yellow blaze of cannon, black flakes of men spattering upward into a white sky, and then the smoke was too thick and he could not see anything and it was like going blind. A paralysis came over him. He sat staring off into the white sea where the guns still flashed and boomed softly, at a great distance, until he saw the first men beginning to come back out of the smoke.