Because of the mistakes committed by Hooker. They were:

1 - He ordered to the VI and I Corps successful landed at Fredericksburg after crossing the River Rapahannock on April 29, 1862, to form a strong bridgehead limiting themselves to defend it. Therefore they remained idles on the place.

2 - In the evening of the same day he sent the whole Stonemans's Cavalry Corps, out of 1,250 men, to carry a raid behind the Confederate lines, thus depriving his army of the indispensable support of scouting and covering.

3 - After brilliantly managing to seize the pivotal position of Chancellorsville, with 54,000 men, after a while increased up to 75,000, Hooker claimed " to wait for Lee's attack to come". Instead to carry hastily on the outflanking movement towards Fredericksburg, he advanced in a very slowly and hesitant way as he were being caught by "the fog of war". Evidently the fatal effects of the absence of his cavalry began to be felt.

Lee took advantage of those mistakes and decided to split his army into two part.

He left 10,000 men at Fredericksburg to guard and keep at bay the inactive Union Corps standing there.

He sent four divisions (McLaws of I Corps, A.P. Hill, Rodes and Colton of II Corps and Stuart's Cavalry Corp., to join the division Anderson (for a total of about 52,000 men) and form a defensive line at Tabernacle's Church to face and check Hooker's 75,000.

When his divisions clashed against the Confederate entrenchments, finding a sturdy resistance, Hooker, ignoring how strong the opponent were and lest of being outflanked, ordered to withdraw back to Chancellorsville, where the army had to stand on the defensive.

At that point, Lee received intelligence from his cavalry, that informed that the extreme Union wing near Wilderness Church was based "on the nought" and therefore susceptible to be outflanked and attacked from the back.

He then decided to further split his army in front of the enemy and ordered his II Corps and Fitzhugh's cavalry division (30,000 men) under Stonewall Jackson to put in motion the relevant displacement and carry out the assault, , which was successful and turned over the battle in favor of Confederate army.

The Civil War broke out on April 12, 1861. The Battle of Chancellorsville took place from May1 to May 4,1863.

Because Lee and Jackson were both performing at their best - as an unbeatable team.

The Union commander Hooker had formed a perfectly sound plan, but Lee managed to wrong-foot him, forcing him to fight where he wasn't expecting to. This threw Hooker off-balance, and he was not properly on-guard when Jackson launched a wild attack on his flank.

Hooker might have taken some consolation when Jackson was killed on the second day, and neither Lee nor his army would ever be the same again. Yet it was a resounding defeat for the Union.

Robert E. Lee - with a lot of help from Stomewall Jackson, killed (supposedly by accident) at this battle.

In an nutshell:

1)The outflanking of the Confederate positions' on the Rappahannock by the bulk of the Army of the Potomac crossing the Rapidan at Germanna Ford, followed by the crossing the Rappahannock of Union II Corps at Bank's Ford.

2) Deployment of the aforesaid bulk behind Lee's Army at Chancellorsville.

3) Crossing the Rappahannock by Union VI and I Corps south of Fredericksburg followed by a demonstrative attack on the Confederate right wing there.

The plan aimed to an encirclement of Lee's Army, forcing them fighting on two fronts, outnumbered and doomed of being destroyed or scattered.

the people did something bad that made the other people mad

The Battle of Chancellorsville.

Joe Hooker

The Battle of Chancellorsville was in the end, won by the Confederacy tactically but it was a HUGE strategic failure. Because of a friendly fire incident, one of the Confederacy's best generals, Thomas "Stonewall" Jackson, died of pneumonia through an infected wound. Many historians believe that had Jackson lived, the Confederacy would have won at Gettysburg. Lee would never find a general as brilliant as Jackson again.

About ten days after the Battle of Chancellorsville, the Confederate's Supreme

Command decided to invade the Pennsylvania via Shenandoah Valley

The motivations were:

take the war the enemy territory's inside;

gain a decisive victory by means of a pitched battle to be fought in a place previously chosen there;

obtain from France and Great Britain the acknowledgement of the Confederacy as independent Nation.

Lee's Army was able to elude the Army of Potomac lined up on the Rappahannock's northern bank and going westward along the route Culpeper, Front Royal, Winchester, crossed the Potomac at Williamsport, entering then in Pennsylvania, outbalancing the Union forces, which, outdistanced, had to run after them up to the preordained Gettysburg heights and plains.

Hooker, buoyed by the great numerical superiority he enjoyed, planned to envelope Lee's much smaller army (Longstreet's corps was elsewhere, and Lee had less than 50,000 men against Hooker's 113,000). He had cavalry patrols searching for rebel movements, and halted his advance until news was forthcoming.

Lee split his army, leaving 10,000 men with General Early to watch General Sedgewick's corps at Fredericksburg. He sent Jackson's corps of 26,000 men on a 12 mile flanking march, while he confronted Hooker's army with less than 15,000 troops.

Around 3 in the afternoon, Jackson's corps burst out of the forest on Hooker's exposed right flank, and drove the federals into a panic rout, the Yankees fleeing and even dropping weapons on the way. Jackson was wounded later that night, and Cavalry commander Jeb Stuart took command.

The two armies grappled again the next day, but Hooker had lost the initiative, and retreated.

The outcome was one of Lee's most magnificent triumphs, being outnumbered as he was.

By mid 1863 the South was facing a shortage of men able to withstand the rigors of war. With the loss of approximately 12000 men in killed, wounded and missing, the Army of Northern Virginia would have difficulty in recovering that loss of manpower. Many of the wounded would eventually return but the over 1500 dead would not. Add to this the loss of one of Lee's ablest generals in the form of Stonewall Jackson, the damage was tremendous and irreparable. One other fact to point out is that the Battle of Gettysburg was exactly 2 months away and one can only wonder "what if" Chancellorsville had not occurred.

Union, commanded by Joseph Hooker, had O.Howard, P.Burnside, Hancock, Meade, and others..Confederate army was commanded By Robert E. Lee, and T.J. Jackson, Jeb Stuart, McLaws, Early, Ewell, Hampton, W.H.F. Lee, others.

The commanding general of the Southern army was General Robert E. Lee.