Image from New York State Library
J. W. Reid of the 4th South Carolina Infantry recorded his impressions of the fighting at Bull Run in a series of letters following the battle in July 1861, republished in the regimental history written by Reid. The 4th South Carolina was part of Evans's brigade during the battle.
I scarcely know how to begin, so much has transpired since I wrote you last; but thank God I have come through it all safe, and am now here to try and tell you something about the things that have just happened. As you have already been informed, we were expecting a big fight. It came; it is over; the enemy is gone....
I cannot give you an idea of the terrors of this battle. I believe that it was as hard a contested battle as was ever fought on the American continent, or perhaps anywhere else. For ten long hours it almost seemed that heaven and earth was coming together; for ten long hours it literally rained balls, shells, and other missiles of destruction. The firing did not cease for a moment. Try to picture yourself at least one hundred thousand men, all loading and firing as fast as they could. It was truly terrific. The cannons, although they make a great noise, were nothing more than pop guns compared with the tremendous thundering noise of the thousands of muskets. The sight of the dead, the cries of the wounded, the thundering noise of the battle, can never be put to paper. It must be seen and heard to be comprehended. The dead, the dying and the wounded; friend and foe, all mixed up together; friend and foe embraced in death; some crying for water; some praying their last prayers; some trying to whisper to a friend their last farewell message to their loved ones at home. It is heartrending. I cannot go any further. Mine eyes are damp with tears.... Although the fight is over the field is yet quite red with blood from the wounded and the dead.
I went over what I could of the battlefield the evening after the battle ended. The sight was appalling in the extreme. There were men shot in every part of the body. Heads, legs, arms, and other parts of human bodies were lying scattered all over the battlefield.
Source: History of the Fourth Regiment of South Carolina Volunteers