Lee performed well in the Maryland Campaign of 1862, covering the Confederate infantry's withdrawal from South Mountain, delaying the Union Army advance to Sharpsburg, Maryland, before the Battle of Sharpsburg around Antietam Creek, and covering his army's recrossing of the Potomac River into Virginia. Stuart's cavalry made its second ride around the Union Army in the Chambersburg Raid before returning in time to screen Robert E. Lee's movement towards Fredericksburg where the cavalry defended the extreme right of the Confederate line. Fitzhugh Lee conducted the cavalry action of Kelly's Ford (March 17, 1863) with skill and success, where his 400 troopers captured 150 men and horses with a loss of only 14 men. In the Battle of Chancellorsville in May 1863, Lee's reconnaissance found that the Union Army's right flank was "in the air", which allowed the successful flanking attack by Maj. Gen. Thomas Jonathan "Stonewall" Jackson, a movement led by Lee's cavalry.