Death of Major General John Sedgwick

As he directed troop placement, General Sedgwick, as was typical of commanders at this point in the war, made a point of not responding to distant enemy gunfire, and laughingly chided the soldiers who dodged when they heard the long shrill whistle of a Whitworth bolt cutting through the air.

"What! What! men, dodging this way for single bullets!" said Sedgwick. "What will you do when they open fore along the whole line? I am ashamed of you. They couldn't hit an elephant at this distance."

A second Whitworth round whistled by, and a soldier spoke up and tole the general he believed in dodging, for he had once dodged a shell that would have taken his head off otherwise. Good naturedly, Sedgwick told the man to take his position.

And now, the third shot from the .451 caliber Whitworth rifle came whistling in, as staff officer McMahon resumed talking to General Sedgwick. According to McMahon, "For the third time the same shrill whistle, closing with a dull, heavy stroke…..

While it isn't known for sure which Confederate sharpshooter actually killed General Sedgwick, the most likely to me seems to be "Kansas Tom" Johnson, who himself died a few days later in battle. But the question has never been wholly resolved, partly due to the reluctance at the time for anyone to claim credit for it.

http://www.civilwarbattlefields.us/spotsylvania/sedgwick.html