On the second day of battle, most of both armies had arrived. The Union line held the high ground in a defensive formation that looked like a fishhook. On July 2, Lee ordered General James Longstreet, commander of the Confederate I Corps, to attack the Union left flank as early in the day as possible. At the same time General A. P. Hill's corps was to attack the Union center. General Ewell was to make diversionary attacks and "if practicable" attack the Union Army's right flank. Lee felt that if everything went according to his plan and the Union line was destroyed, the battle, and possibly the war, would be won on the second day. Lee's coordinated attack required getting all the infantry into position and moving up artillery to support them. Longstreet had the furthest to go and midway in their march realized the Union lines could see them. They went back and had to take a different route. Longstreet could not get his corps into position until about 4 p.m. when he began his attack. His attack on the Union line lasted for over three hours but could not break the Union line. Hill's Corps failed to be effective in the center. Ewell did not attack Cemetery Ridge as instructed in Lee's confusing order, but made some progress in taking Culp's Hill.