Richmond, but Lincoln vetoed that idea because Hooker's goal should have been fighting and defeating the Confederacy's most important army in the field, Lee's Army of Northern Virginia. When Hooker demanded control of the garrison at Harper's Ferry or he would resign, Lincoln called his bluff and replaced Hooker with George Meade on June 28, just 3 days before the battle started. The new commander brooked no delay in chasing the rebels north. Meade's advance was sluggish but was further advanced than Lee knew. Lee underestimated his new foe, expecting him to be easy to anticipate and slow to respond, much like Hooker. Meade wanted to defend further south, but when battle was joined at Gettysburg he hastened all corps there. Taking advantage of interior lines, Meade was close behind Lee, and had cut off the line of retreat back to Virginia. Lee had to fight, but first he had to rush to reassemble his scattered forces at the crossroads town of Gettysburg before Meade defeated them piecemeal. Lee had 60,000 infantry and 10,200 cavalry (Meade's staff estimated Lee had 140,000). This time it was Lee's turn to be fooled; he gullibly accepted misinformation that suggested Meade had twice as many soldiers, when in fact he had 86,000. Though the main Confederate army was marching through Pennsylvania, Lincoln was unable to give Meade more firepower. The vast majority of the 700,000 Federal soldiers (except for Grant's 70,000 near Vicksburg) were noncombatants that held static defensive posts that Lincoln feared to uncover, or like Rosecrans at Nashville, they were afraid to move. Urgently the President called for 100,000 civilian militiamen to turn out for the emergency; being unorganized, untrained, unequipped and poorly led, they were more trouble than they were worth. When the battle began they broke and ran away. Campaign timeline The battles of the Gettysburg Campaign were fought in the following sequence; they are described in the context of logical, sometimes overlapping divisions of the campaign. Lee's advance to Gettysburg On June 3, 1863, Lee's army began to slip away northwesterly from Fredericksburg, leaving A.P. Hill's Corps in fortifications above Fredericksburg to cover the departure of the army, protect Richmond from any Union incursion across the Rappahannock, and pursue the enemy if Hill thought it advantageous. By the following morning, Hooker's chief of staff, General Daniel Butterfield, had received various reports that at least a portion of the Confederate