After each engagement, there were adjustments. After Gettysburg, some were technical and incremental. The Army of the Potomac copied the Army of Northern Virginia's system of fewer but larger corps. The ANV copied the AoP's system of army wide artillery reserves. After Gettysburg, Lee had some artillery under his direct control, rather than attaching it all to Corps and Division commanders.
Lincoln was not content with just victory. He did not want the ANV driven back south defeated. He wanted it destroyed or surrendered. This was expecting much. Few victories in the Civil War were so complete as to destroy armies. Gettysburg was a victory, but not a decisive victory giving overwhelming advantage. Meade's pursuit might have been judged timid by people sitting behind a desk far away, but it was a realistic pursuit given that the AoP was hurt almost as much as the ANV. Neither side felt they had sufficient advantage on July 4 to attack. Longstreet's July 2nd comment might apply to July 4th as well. "If he is there tomorrow, it will be because he wants you to attack him." Both armies stayed on the Gettysburg field an extra day, in sufficient condition to defend, with good ground to defend, but in no condition to attack. The South might be said to have left the field as much due to supply considerations as because they were hurt more then their enemies.
"I believed that General Meade and his noble army had expended all the skill, and toil, and blood, up to the ripe harvest, and then let the crop go to waste."
Founding President - Gettysburg Second Guesser's Club
If Lincoln's judgment of Meade's timid pursuit was harsh, his action was correct. While there were many generals in the Civil War that could win victories, there was one who destroyed opposition armies. Lincoln brought Ulysses S. Grant east. Following Gettysburg, both Lee and Meade paused to rest and refit. Grant changed this. Win, lose or draw, after the AoP fought under Grant, it would shift to the left and fight again. Grant didn't seek a decisive battle, then give the opposition time to recover if the battle was not decisive. He fought a decisive campaign. He could afford to bleed his army more than Lee. By keeping up the pressure in the east, Lee couldn't send units of the ANV west. Even if Grant had failed to destroy the ANV, his approach would have given the western armies opportunity to destroy the South.
The war changed after Gettysburg, but Grant's victory at Vicksburg on July 4 was perhaps more important. Meade's victory was empty in the military sense, though in the political sense it may have been decisive in aiding Lincoln's 1864 reelection. Grant captured his opponent's army entire, and thus was brought east to do the same to the South's greatest army.
The Gettysburg campaign is properly judged the South's last best chance. The 'what ifs' are endless. Most of them center on increasing of southern aggression. Some of these 'what ifs' might be valid. Lee and Stonewall together could and did fight and win a aggressive offensive battles in an era where the weapons were beginning to favor the defense. It might be too strong to say that Lee alone could not fight offensively. It seems fairer to say Lee adapted to the style of his most able lieutenant. Before Gettysburg, Lee and Jackson were slashing attackers, spreading or splitting the army, using flanking attacks, pushing the initiative. After Gettysburg, Lee and Longstreet fought more often on the defensive, using the terrain and preserving their manpower. The tragedy for the South is that Lee could not anticipate the need for a change. It took a losing battle for Lee to adjust his style to the loss of Stonewall Jackson. However, it is much to expect Lee to fix something that hadn't be shown to be broken. It is to be expected that he would try again what had consistently worked in prior battles.
Meade published an account of the Gettysburg campaign several months after the battle. Longstreet acquired a copy, and showed it to Lee. By Longstreet's account, Lee conceded that Longstreet had been correct on the field. The South would have been better served being 'offensive in strategy, but defensive in tactics.' After Lee's death, this debate was reopened, and will likely rage on indefinitely. The opinions are many and varied. Still, if one wishes to see Lee's opinion, review his final campaign. There, Lee most often claimed the lovely ground, and yielded to Grant the initiative. The Union began to take its shares of victories, but paid the aggressor's bill in blood.
'What-ifs' are distinctly different from lessons learned. Given 20-20 hindsight, infinite time to think and no pressure to perform, a historian might improve on a general's judgment. This is an easy game that anyone can play. Historians earn less fame and glory than generals, and properly so. Suggesting that if Stuart stayed with the main body, Lee might have concentrated sooner and initiated battle with more information is a fine what-if. I'm not sure. If Stuart was with the main body, would Meade have dispersed his army as much? Thus, while this is a fine what--if, it is not my favorite. This illustrates a fatal problem with the hobby of what-iffing. It is easy to suggest how doing something different might have produced a different result. It is less easy to achieve agreement on what that different result might have been.
For the South, I'd ask what might have happened if Johnson's division had traveled straight south with Rodes, avoiding the Cashtown Gap bottleneck, leaving the roads open for Pickett to reach the field on July 2nd. When Lee learned the AoP was north of the Potomac, his first order was for everyone to concentrate west of South Mountain. The second was to concentrate near Gettysburg. This indecision might have been expensive. Had the initial order focused everyone east of South Mountain, two Southern divisions might have reached the field a day sooner. The battles were close enough on July 1st and 2nd that a division in the South's favor would have been very significant. Still, if Buford's scouting had been as accurate in this what if as it was historically, would he and Reynolds have attempted to hold Gettysburg on July 1st against five southern divisions? I suspect Buford and Reynolds would not have tried to hold Gettysburg, that Lee would have concentrated near Gettysburg while Meade formed up at Pipe Creek. Would Stuart have had a chance to link up with Lee before the fighting started? Again, the crystal ball gets hazy.
My other favorite for the South is Lee listening to Longstreet on the morning of July 2. What if they had pulled a Grant? When the position in one's front is too strong, move to the side, threaten the opposition's capitol, force the opposition to move, and see if the new situation is more favorable? There is a problem with this one. If both Meade and Longstreet wanted to find good defensive ground and await attack, who would give in first and take the offensive? Given Lee's past success on the offensive with Stonewall, and that the North showed no inclination to take the offensive in the battle as it was fought, the answer seems obvious. Longstreet was not going to fight defensively. The most likely result of a strategic flanking maneuver would be a variation on the battle as it was fought, but fought somewhere else, though likely the ground might have been less in the Union's favor. If this what-if supposes Longstreet could persuade Lee not to attack Cemetery Ridge, would it also propose Longstreet could prevent an attack on the more formidable Pipe's Creek position? While it is not certain the Pipe's Creek plan would have been Meade's response to Longstreet's proposed strategic move to the right, it seems a reasonable guess. If so, Longstreet might have balked again, and wanted to shift right again. Such conjectures have too many variations for exploration with certainty.
For the North, what if Sickles had stayed put? Longstreet's July 2 assault might have been repulsed with less mixing of Union Corps and fewer casualties. Longstreet might have been caught in the flank and rear by the III and V Corps. At battle's end, might the Army of the Potomac been in condition for vigorous pursuit, rather than cautious pursuit? If the northern army had been in condition for vigorous pursuit, would their generals have been aggressive enough to try it?
A second northern what if also centers on Sickles. On July 1st, General Reynolds was in command of the left wing of the AOP, the I, III, and XI Corps. On the recommendation of General Buford, Reynolds committed the left wing to defend Gettysburg. There was a problem. General Sickles received two orders that morning, at roughly the same time. Reynolds ordered the III Corps north to Gettysburg. Meade ordered the III Corps east to form the Pipe Creek line. Sickles dithered, sending messengers to clarify the conflict, obeying neither order.
Colonel Vincent is regarded as a hero, saving Little Round Top, by ignoring the chain of command. He followed the direction of General Warren without informing and getting approval from his division and corps generals. Sickles' handling of conflicting orders on July 1st shows why following the chain of command is both tedious and proper. By giving orders to Sickles directly, Meade could have saved serious time in forming is Pipe Creek line. Reynolds was at the front, Meade well in the rear, Sickles in the middle. On the other hand, Reynolds had committed his force to battle at Gettysburg, thinking he had three army Corps. Meade's order to Sickles effectively reduced the left wing to two corps with no notice to Reynolds. The situation was further confused by Reynolds' death. By the time the III Corps finally arrived at Gettysburg, the I and XI Corps had been defeated. With 20 20 hindsight, as we know the battle was fought at Gettysburg, Sickles clearly should have moved forward, disregarding the overly cautions orders of the army commander to retreat to Pipe Creek.
Could the fiasco of July 1st have influenced Sickles' decision on July 2nd? In his congressional testimony, Sickles testified to Meade's unwillingness to fight at Gettysburg and how the first day's fighting is not important. This is more spin than fact, and more true on July 1 than July 2.
Did Meade's July 1st order to Sickles to retreat to Pipe Creek cost the Union the first day of the Battle of Gettysburg? Would the III Corps have arrived before the XI Corps broke? Would the III Corps have been enough to turn the tide? If the Union had won or tied on July 1, would they have retreated to their fish hook line south of town and fought defensively, or might the whole battle have been fought differently?
Sickles July 1st dilemma also illustrates why the AoP was later reorganized into fewer but smaller Corps. In reading more detailed accounts of the battle, one will find tales of how Reynolds, Warren and Hancock were at the front, making sound tactical decisions, saving the day, earning good press. Meade was an off stage presence, staying well to the rear. Reynolds, Warren and Hancock were the wing commanders, taking command of two to three adjacent corps. They performed heroically. Meade was back in the rear. Note, however, that whenever Warren or Hancock desperately needed reinforcement to save the day, in the nick of time a reinforcing unit showed up at the right place, at the right time, barely. Meade did his job. With fewer but larger corps, there was less need for wing commanders. Through the whole battle, Meade had to pull a corps commander or staff member out of the normal chain of command, creating ad-hock organizations. Still, even with fewer but larger corps in 1864 and 1865, Grant frequently used Sheridan as a wing commander. Perhaps no rigid organization was sufficient. The commanding general needed the ability to create ad-hoc forces.
My final what if proposes the unthinkable, a northern attack. If one is on the offensive, one wishes to strike the enemy in the flank and rear. If one is on the defensive, one wants to curl one's line's back, making it more difficult for an attacker to reach one's flank and rear. As a result, the attacking army is apt to end up with exterior lines, the defender interior lines. Exterior lines make it easier for the defensive army to switch to the attack, to hit the opponent's flank and rear.
Pickett was Lee's last fresh division.
The VI Corps was Meade's last fresh Corps
Johnson is in a lonely position, the tip of the fish hook.
To the right, both armies curl back, protecting their own
Above, the July 3rd positions. Lee, thinking aggressively, used his last fresh unit as the core of his attack. Meade, thinking defensively, used his last fresh unit to patch up weak points in his line. The VI Corps' three divisions ended up guarding both flanks and the Hole where Sickles' III Corps had been decimated the previous day. If Meade had been thinking aggressively, had been willing to leave the south of his line weak, there is the possibility of hitting Johnson's division in the flank and rear. Johnson's division was both isolated and tired from prior days fighting.
I can't fault Meade too much for remaining defensive. Lee seemed willing to fight uphill battles. Accepting good defensive ground, yielding initiative, was more conservative and it worked. Also, Johnson had a hill to his northeast. Unless the North achieved total surprise, he could have shifted to decent defensive ground. Lee was massing troops in his center for Pickett's Charge. While the VI Corps might have had good initial success against Johnson, the town of Gettysburg would have broken up any continuation of the attack to roll up the southern army. The strong Confederate center could have easily turned to stop a one corps attack. While Johnson was isolated and exhausted, hitting him would not have ended the battle. Remaining defensive was likely the better option.
While the what-ifs spin rapidly off into numerous possibilities. The associated lessons learned are less nebulous. For the South, Stuart did not make a third ride around the Army of the Potomac. While his eastward diversion may have had merit, it was not tried again. For the North, while some Civil War generals fought on after losing a leg, Sickles did not. Hopefully, this too might be counted as a lesson learned.