Chancellorsville+5

Joseph Hooker was appointed to command and planned to attack Lee's army while many of them were in the Suffolk area. He was convinced that the Confederates would surrender to his trap. When Lee found out about what Hooker had done, he sent General Richard H. Anderson to investigate. The Confederates did not plan on surrendering, as Hooker had predicted, and they tried to block the Federals. The Federates had managed to slip by the Confederates, but soon, their cavalry raid would go wrong and they would end up in the wilderness. Lee still did not plan on retreating, even though he only had about 60,000 troops, while Hooker had 115,000. Lee split his army and put half in Fredericksburg and used the other half to attack Hooker's army. Hooker brought his troops back to Chancellorsville on May 1 where he made a defensive line. On May 2, Stonewall Jackson of the Confederate army planned to attack the Confederates, but confusion caused him to be accidentally shot in the arm by his own men. Lee caused the Federals to retreat and cross the Rappahannock. In the end, the battle at Chancellorsville was known as Lee's greatest victory. The Confederates suffered 14,000 casualties, and the Federals had 17,000 casualties.

Sources: http://www.civilwarhome.com/records.htm