After the Federals lost the race to Spotsylvania the previous day, both armies brought up more troops and worked on their entrenchments on May 9th. Lee's line was formed into a semi-circle to meet threats from several directions. The apex of the line was known as the Mule Shoe for it shape. Although it extended dangerously far from the main Confederate line, Lee's engineers believed this was necessary to hold a piece of high ground.
At around 9 pm Union Major General John Sedgwick went out to supervise the placement of artillery along his corps' line. There was one point along the line where Confederate sharpshooters about 1,000 yards away had been particularly active, and Sedgwick saw his men ducking and dodging as bullets whistled overhead. “What?" Sedgwick remarked, "Men dodging this way for single bullets? What will you do when they open fire along the whole line? I am ashamed of you. They couldn't hit an elephant at this distance." Seconds later he was proved wrong, as a sharpshooter's bullet struck him just below the left eye. He may have been dead before he hit the ground. He was the highest ranking Federal casualty during the Civil War.