Lee's confidence was unshaken by the events of July 2. That night, he ordered Longstreet, who had been reinforced by Major General George Pickett's division, to renew his assault on the Federal left. Simultaneously, Ewell, who had also been reinforced, was to storm Culp's Hill. Stuart's cavalry, which had rejoined the army late that day, was ordered to march well east of Gettysburg, and attempt to penetrate to the Federal rear where they might disrupt communications and distract Meade.
Meanwhile, Meade had determined to hold his position and await Lee's attack. However, at Culp's Hill he authorized XII Corps to drive Ewell's forces out of the captured Federal trenches at daylight. The Federal effort opened with a concentrated artillery bombardment which precipitated a tremendous musketry battle.
With Ewell already engaged, Lee rode to Longstreet's headquarters to observe his preparations for the attack on the Federal left. Longstreet misunderstood his orders and was planning instead a movement to turn the Federal left. With the hope of a coordinated attack now lost, Lee was forced to modify his plans. He determined to shift his main attack to the Federal center on Cemetery Ridge. Longstreet was placed in command of the effort. The plan was first to subject the Federal position to bombardment by nearly 140 cannon, then to send Pickett, Pettigrew and half of Trimble's divisions (formerly Heth's and Pender's) - nearly 12,000 men - forward to smash the Federal center.
While Longstreet made his preparations during the morning, Ewell's forces were defeated in their counterattacks on Culp's Hill, and withdrew around 11:00 a.m.
At l:00 p.m., Longstreet opened the great bombardment of the Federal line. The Federal army replied with approximately 80 cannon and a giant duel ensued which lasted for nearly two hours. After the bombardment subsided, the infantry went forward. This has subsequently been known throughout history as "Pickett's Charge." Federal artillery, followed by musketry, cut their formations to pieces and inflicted devastating losses. A small Confederate force effected one small penetration of the Federal line, but was overwhelmed. The attack ended in disaster, with nearly 5,600 Confederate casualties. Meanwhile, three miles east of Gettysburg, Stuart's cavalry was engaged by Federal cavalry under Brigadier General David Gregg. The cavalry clash was indecisive, but Stuart was neutralized and posed no threat to the Federal rear.
The battle was effectively over. Federal losses numbered approximately 23,000, while estimates of Confederate losses range between 20,000 and 28,000
