The Battle of Chancellorsville was a famous battle of the American Civil War, occurring between May the 1st and 4th, 1863, during Joseph Hooker's command of the Army of the Potomac. The Federals numbered 100,000 troops; the Confederates under Robert E Lee, who lay on the west side of the Rappahannock River, were about 90,000 strong. Robert E Lee had, during the winter, constructed an impregnable line from Bank's Ford to Port Royal. Joseph Hooker dispatched Sedgwick across the river to menace Fredericksburg, and Stoneman's cavalry to attack Robert E Lee's rear, while he, with the main column, intended crossing lower down the stream and assaulting the Confederate flank. Before Robert E Lee was aware he had moved, he was established at Chancellorsville with 46,000 troops. Robert E Lee at once decided to begin the attack. On May the 1st several short attacks were made upon the Federals to ascertain their position and strength. On May the 2nd Jackson, with 26,000 Confederates, making a long detour swept down upon Joseph Hooker's left under Howard, and completely demolished it. The counter charge of Keenan's Pennsylvania troops alone saved the left from utter destruction. Late in the afternoon StonewallJackson was fired upon by mistake by his own men and mortally wounded. On May the 3rd the fight was renewed with terrible vigour. Robert E Lee and Jeb Stuart combined forces and attacked Joseph Hooker's centre. Joseph Hooker himself was wounded, and the National line became completely demoralized. The Federals were rapidly forced back to some strong entrenchments that had been constructed the previous night. Just then Robert E Lee heard that Sedgwick had captured Fredericksburg heights, and was advancing upon his rear. His attention was turned to defeating Sedgwick. Joseph Hooker retreated, beaten and in confusion. Research Battle of Chancellorsville