[M]y plans are perfect, and when I start to carry them out, may God have mercy on General Lee, for I will have none.” So said Major General Joseph Hooker in mid-April 1863 to a group of Union officers about his strategy for defeating Robert E. Lee and the Army of Northern Virginia. Hooker, who had assumed command of the Army of the Potomac in late January, had spent the previous months reorganizing his own force and gathering intelligence on the enemy, and was now supremely confident that his planned offensive—to attack both flanks of Lee’s army simultaneously—would succeed. Lee, however, seized the initiative, splitting his smaller army not once, but twice, sending Thomas J. “Stonewall” Jackson’s corps on a devastating attack against Hooker’s right flank on May 2, then following up this success with further assaults against the Union position at Chancellorsville. By May 7, Lee and the Confederates had scored a clear (though costly) victory against Hooker’s army, prompting President Abraham Lincoln reportedly to remark, “My God! My God! What will the country say?” Below we highlight renditions of the decisive battle, which had produced an estimated 30,000 Union and Confederate casualties.