Stuart’s absence was a severe handicap for Lee. He discovered the proximity of the Union army only because of information provided by a spy that Longstreet had hired. But once he got a sense of the enemy’s location, Lee adopted a characteristically aggressive concept of operations. He wrote to Major General Isaac Trimble, “I shall throw an overwhelming force on their advance, crush it, follow up the success, drive one corps back on another, and by successive repulses and surprises before they can concentrate, create a panic and virtually destroy the [Army of the Potomac].”
Still, Lee wished to avoid a general engagement until he had concentrated his army. Although two of his corps were converging on Gettysburg from the north and the west, Longstreet would not be up until late the next day. But as Napoleon is reputed to have remarked, “A dogfight can initiate a battle.” At 5:30 a.m. on the morning of July 1, the lead element of Hill’s corps (Henry Heth’s division), approaching from the west on the Cashtown Pike, clashed with Buford’s cavalry on McPherson’s Ridge west of town.
The Battle of Gettysburg was on. Meade now had no choice but to abandon his Pipe Creek defensive plan and push the Army of the Potomac north toward Gettysburg.
Heth’s division deployed from column into line and advanced against Buford’s dismounted troopers on McPherson’s Ridge. Despite being outnumbered, the cavalrymen, armed with repeating carbines, were able to deliver a high volume of fire and gave ground only grudgingly. Heth nonetheless pushed forward to McPherson’s Ridge, where he encountered Reynolds’s I Corps, which checked his advance. Around 10:30 a.m., Reynolds was killed by a Confederate sniper, and command of I Corps fell to Abner Doubleday. There followed a lull in the battle as I Corps redeployed to Seminary Ridge and both sides awaited reinforcements.
At about noon, Major General O. O. Howard’s XI Corps arrived and deployed to Doubleday’s right, facing north to deal with the approach of Ewell’s corps from Carlisle. Lee also reached the field about this time. Without intelligence from Stuart, Lee still did not know the full disposition of the Federal army. As he wrote to General Richard Anderson of Hill’s corps, “In the absence of report from [Stuart], I am in ignorance of what we have in front of us here. It may be the whole Federal Army or it may be only a detachment. If it is the whole Federal force, we must fight a battle here.”
At about 2:00 p.m., Rodes’s division of Ewell’s corps, joined by Heth, struck the right of the Federal I Corps. About an hour later, Jubal Early’s division of Ewell’s corps attacked down the Harrisburg Road, smashing the exposed right of the XI Corps, a repeat of that unfortunate corps’ experience two months earlier at Chancellorsville when Jackson’s attack had routed the corps and rolled up the entire Union line. The routed Federals retreated through Gettysburg to Cemetery and Culp’s Hills, the high ground south of the town. Meanwhile the Federal I Corps on Seminary Ridge also gave way before Hill’s assault.
Lee ordered Ewell to press the attack against the new Union position “if practicable.” Proving he was no Stonewall Jackson, Ewell declined. Meanwhile Major General Winfield Scott Hancock arrived on the field in advance of his approaching II Corps. Much to the consternation of Howard, who was senior to Hancock, the latter announced that Meade had ordered him to assume field command of the Union forces. Howard accepted the slight and worked with Hancock to strengthen the Union position while Hancock pressed Meade to bring up the rest of the Army of the Potomac as quickly as possible.
During the first day of battle, Lee had shattered two Union corps, inflicting 9,000 casualties, including 3,000 captured, while suffering 6,500 of his own. The Union I Corps alone lost some 5,700 soldiers, including 1,500 captured. Some units bore the brunt of the battle: for instance, the 24th Michigan, a regiment of the famed “Iron Brigade,” the only all-western brigade in the Army of the Potomac, lost 399 of its 496 soldiers. Although the Union position on Cemetery and Culp’s Hills was strong, the soldiers of the I and XI Corps were demoralized. Had Ewell proven to be as aggressive as Jackson, it is likely that the Confederates would have carried the Federal position on the evening of July 1.
Lee and Longstreet: On the Cusp of Victory
Both armies were reinforced during the evening of July 1. Longstreet arrived with two of his three divisions (George Pickett’s division was still a day’s march away), and three more Union corps reached the battlefield. (It should be noted that Union corps were about half the size of Confederate corps at that time.) The Union position began to assume the shape of a fishhook, with the barb and bend running west from Culp’s Hill to Cemetery Hill, and the shank running south along Cemetery Ridge toward two rises, Little Round Top and Round Top.
Encouraged by his success on the first day, Lee resolved to renew the attack on July 2. An early-morning reconnaissance revealed that the Union line extended about halfway down Cemetery Ridge, short of the high ground of Little Round Top. Lee ordered Longstreet to take his two present divisions under major generals John Bell Hood and Lafayette McLaws and attack the Union left.
While Ewell demonstrated against the Union right on Culp’s and Cemetery Hills, Longstreet, supported by a division of Hill’s corps on his left, was to deliver a flank attack on the Union line. However, Lee was informed that the Union line on Cemetery Ridge had been extended south, so he modified his original plan and directed Longstreet to attack en echelon from south to north.