Gen. George G. Meade of the Army of the Potomac sends Maj. Gen. Winfield Hancock to Gettysburg to take full command until Meade arrives. Lee arrives on Herr Ridge while 9,200 troops take position North of Gettysburg. Gen. Jubal Early's 5,500 Confederates arrive on the Harrisburg Pike and attacks the Federals there. Lee sends two of Heath's Brigades forward South of Chambersburg Pike reopening the front.
Federals pull back to Cemetery Hill.
All Federal forces move back to Cemetery Hill. Gen. Henry Slocum arrives with 10,000 men and assumes command from Hancock. The main strength of both armies has arrived on the field by the morning hours. General Lee launches attacks against the Union left and right in an attempt to dislodge Meade's army from its strong position. Longstreet's assault upon the Union left makes good progress but is eventually checked by Federal reinforcements from the center and right.