While Lee was a good general, I would not descibe him as amazing. In all his battles, he lost a higher percentage of his own forces than he managed to cause the enemy, making his campaigns unsustainable in the long run.

As for Pickett's charge, it was not enitrely an unwise decision, however, it was poorly carried out.

The Confederates had attacked on the Union flanks on the first two days of the battle, and since Stuart and his cavalry had arrived, it looked like another attempt to flank the Union line was going to come on day 3. Meade had reinforced his flanks and thus the centre looked relatively weak.

The intention was to silence the Union artillery in the centre and place a Napoleonic grand battery style barrage on the Union centre to hinder movement of reinforcements and disrupt the Union formations. Pickett's division, supported by Pettigrew's and Anderson's would charge straight ahead, not stop to fire and charge the Union position with bayonets.

At the same time Stuart and his cavalry was to flank the Union line and disrupt it, inserting itself between the Union lines of retreat and the Union forces.

If successful the attack would have broken the Union centre and more or less surrounded the Union right (northern) flank, hopefully causing an army-wide rout and a huge victory for the Confederates, with Stuart's cavalry in an excellent position to force fleeing Union forces to surrender, capture artillery and supply trying to retreat and so on.

Map of the attack.

Napoleon had done something very similar at the Battle of Austerlitz 1805 - feigning an attack on the flank of the Austro-Russian Army and breaking through its centre.

Several things went wrong. The Confederate artillery proved unable to best its Union counterpart, and had to move its ammunition supplies back to now risk having them hit as the Union artillery engaged in counter-battery fire. This reduced the rate of fire for the Confederate artillery and locked them in an artillery duel with the Union artillery instead of dominating the terrain around the Union positions.

Stuart's cavalry got embroiled fighting the Union cavalry and was never able to get in behind the Union line.

At the same time, as you can see on the map, Pickett's division realised they had advanced along the wrong axis and decided to wheel and march towards their original target - which was probably a cruicial mistake. Such a manouvre takes time when done with large amounts of men in formation, and the Confederate forces were under artillery fire from the Union artillery the whole time.

Once Pickett's division did reach its original assigned point of breakthough, the vast majority of men refused to charge home with bayonets despite specific orders to do so, and instead stopped and started exchanging rifle fire with the defenders, perfectly positioned in the killing zone of the defenders' rifle and canister (case) shot fire.

Only a few hundred men charged home - those that did carried the position but were thrown back by a Union counterattacksince their flanks were exposed by the other men not advancing.

Overall, the original plan was sound, but the Confederate army lacked the resources to carry it out properly. The artillery was unable to do what it was supposed to do, the cavalry got stuck fighting the Union cavalry and the infantry of Pickett's division arrived with enough casualties to deter them from charging home as per their original order. Thus the attack failed.

vonadler has summarized the situation and so far Lee had not lost anything and came from a couple of years of beating the Union over and over, the most recent one in Chancellorsville which was a total shame for the Union once again. Lee always excelled at reading the opponents mind and taking some bets and risks, and so far it worked for him. He was an excellent General, specially at tactical level. Further important considerations:

• Civil War armies fought hand to hand so this mean they were really close to each other once they collided, even camped near by, within a mile sometimes. Doing nothing on the 3rd day would not be an option, you had either to attack or retreat and disengage. The attack we know how it ended but the retreat could have been far worse. You have to turn your back on your enemy while a rearguard tries to keep them at bay, very risky business, normally any sensible General would fall upon your rear and strike, you have no order of battle and may be defeated in detail. And if you retreat, where do you go from there? Back to Virginia? back to a defensive position to try again? how to supply your troops in the meantime? No easy choice.

• Lee was there, with limited supplies and no chance to get any from his base back in Virginia. He had to force a decisive battle, if the Union Army gave way there he would be likely to gather quite some stuff from the Federal train (as he usually did) and create quite a lot of mayhem both militarily and politically but this is "what if" stuff that I do not favor as historian, but Lee surely weighted his options. A potential Union defeat of withdrawal would have set the Northern public opinion very nervous feeling Philadelphia and potentially Baltimore under threat, what about if the remaining of the Federal Army could not stop him in a last ditch battle? would the doors being open to these cities? should peace be negotiated? would European powers recognize the Confederacy? Lee never had time to write his autobiography but I am sure he put all this in the balance.

• The Union was in a very favorable defending position, I'd not say impregnable but certainly a good one. Lee had to know this, he had found himself in the reverse back in Fredericksburg last winter and managed to repel the Federals under Burnside but he still though that they could be dislodged if sufficient pressure could be exerted. It proved otherwise but Lee took his chances.

• One of the longest, hardest and hottest debates of Civil War experts still turn around this 3rd day at Gettysburg. As vonadler says the Confederate artillery was ineffective (they suffer a constant issues along all the war in terms of ammo reliability) and is believed that in fact many rounds actually hit areas well behind the Union main line at the center. In Civil War times once you fired the 1st salvo all became hidden by the smoke and fine tuning for the gun crews was very difficult.

• Longstreet, to me one of the best Corp Commanders of the entire war in both sides, was made a scape goat in the years after the war for his fellow generals and the so called Lost Cause, but part of his criticism to Lee and reluctance to execute Lee's orders can only be seen as accurate now. I think he clearly smelled the flaws in the plan for the 3rd day and in my humble opinion he clearly assessed that the force assigned tot he assault was insufficient.

• One last thing, unfortunately one that can't be proved, is how confident Lee felt those critical 3 days. He came from defeating or repelling the Union Army and his long list of commanding generals over and over in the last 2 years, especially the last 6-8 months. Why he would not be able to gain the upper hand once more? He had taken bigger risks in the past, dividing his army prior to Antietam and still survived, he entrenched in Fredericksburg and repelled the union assaults causing thousand of casualties and provoking Burnside relief from command, he had divided his army once again in Chancellorsville to take the offensive against Hooker and prevailed once again. He had read the mind of all those commanders and anticipated their moves and prevailed, why not once more?

Vonadler makes some great points, as do many other contributors. I would like to hammer home one point that historians now heavily discuss, the fact that the question about the third day always tries to explain why the Confederates lost, rather than why the Union won. Though the Army of the Potomac had the same name, it was by no means the same army that Lee had bested over the past year. Incompetent commanders were increasingly sacked, untrained volunteers were now battle hardened veterans, troop dispositions were far more tactically/strategically sound, and Union officers were more aggressive and independent.

Both Lee and Meade's army suffered under the strain of incompetent commanders who owed their positions to political intrigue. Though these still existed in the Union army, Union commanders were now more inclined to remove these men from positions where they could do untold damage. Furthermore, Lincoln himself had a penchant for removing officers from all levels of command, resulting in an army of professionals. As it so happened, General Hancock's command was at the center, arguably one of the best division and corp commanders the Union had.

Officers were not only becoming professionals, but so were the volunteers in the army. These men, particularly the ones in the center of Meade's line on the third day were battle hardened veterans of some of the toughest regiments the Union had to offer. Furthermore, they sensed the moment, many testified to it at the time. They recognized how critical this day was and each man felt the weight of their nation's fate on their shoulders. Combined with the steadfastness of their commanders, their determination and grit shown that day in the face of the massive assault.

This determined defensive line was well chosen. The ground was in their favor and the placement of artillery was impeccable. It is easy to say that "this is good ground," but you still need to know how to use it to your advantage, which the defenders clearly did.

Lastly, Union commanders were more aggressive and independent than before. Vondaler is right that Stewart's attempts to get around the Union flank were thwarted. Why was it thwarted? Because of numerous near suicidal charges by Union cavalry, led in part by none other than George Armstrong Custer. Custer's cavalry, though outnumbered, stopped the Confederates dead in their tracks, allowing reinforcements to be brought up and alerting Meade to the turning movement. It was the aggressive and independent action of Union cavalry that helped win the day. In the past, Confederate cavalry reigned supreme in nearly every encounter with Union troopers, this one could argue was the beginning of the end of that dominance.

So to sum up, this was a different animal that confronted Lee on the Third Day. Though the Confederates blundered, it was the actions of Union soldiers and commanders at every level that won the day. As one historian put it, rather dryly, why did the Confederates lose that day? The Union army had something to do with it. :-). (Source: Gary Gallagher, Lee and His Generals in War and Memory. Louisiana State University Press, 1998. Gary Gallagher, The Third Day at Gettysburg and Beyond. University of North Carolina Press, 1994. (Editor and co- author))

Thank you everyone, one last comment, if anyone wants to know more the last work on Gettysburg by Allan Guelzo "The last invasion" is a great account of the whole battle and the events that led to it. Highly recommended.

http://www.amazon.com/Gettysburg-Invasion-Allen-C-Guelzo/dp/0307594084