<Li> Stoneman's Raid </Li> <P> The Battle of Chancellorsville was a major battle of the American Civil War (1861--1865), and the principal engagement of the Chancellorsville Campaign . It was fought from April 30 to May 6, 1863, in Spotsylvania County, Virginia, near the village of Chancellorsville . Two related battles were fought nearby on May 3 in the vicinity of Fredericksburg . The campaign pitted Union Army Maj. Gen. Joseph Hooker's Army of the Potomac against an army less than half its size, General Robert E. Lee's Confederate Army of Northern Virginia . Chancellorsville is known as Lee's "perfect battle" because his risky decision to divide his army in the presence of a much larger enemy force resulted in a significant Confederate victory . The victory, a product of Lee's audacity and Hooker's timid decision making, was tempered by heavy casualties, including Lt. Gen. Thomas J. "Stonewall" Jackson . Jackson was hit by friendly fire, requiring his left arm to be amputated; he died of pneumonia eight days later, a loss that Lee likened to losing his right arm . Lee's difficulty in replacing his lost men as well as his inability to prevent the Union Withdrawal effectively have led to his great victory being regarded as a Pyrrhic one . </P> <P> The Chancellorsville Campaign began with the crossing of the Rappahannock River by the Union army on the morning of April 27, 1863 . Union cavalry under Maj. Gen. George Stoneman began a long distance raid against Lee's supply lines at about the same time . This operation was completely ineffectual . Crossing the Rapidan River via Germanna and Ely's Fords, the Federal infantry concentrated near Chancellorsville on April 30 . Combined with the Union force facing Fredericksburg, Hooker planned a double envelopment, attacking Lee from both his front and rear . </P> <P> On May 1, Hooker advanced from Chancellorsville toward Lee, but the Confederate general split his army in the face of superior numbers, leaving a small force at Fredericksburg to deter Maj. Gen. John Sedgwick from advancing, while he attacked Hooker's advance with about four - fifths of his army . Despite the objections of his subordinates, Hooker withdrew his men to the defensive lines around Chancellorsville, ceding the initiative to Lee . On May 2, Lee divided his army again, sending Stonewall Jackson's entire corps on a flanking march that routed the Union XI Corps . While performing a personal reconnaissance in advance of his line, Jackson was wounded by fire after dark from his own men close between the lines, and cavalry commander Maj. Gen. J.E.B. Stuart temporarily replaced him as corps commander . </P>

Who attacked first in the battle of chancellorsville