After his recent Battle of Chancellorsville victory, General Robert E. Lee launched a second invasion of the North on 1 June 1863. Lee was confident as he had a huge army and knew that many enlisted soldiers had left the Union army. He left Fredericksburg and moved northwards towards the Shenandoah Valley, arriving on 3 June. He repelled the Union garrison at Winchester and on 15 June crossed the Potomac. On 28 June, Lee learned that Union forces, now under Major-General George Meade, were beginning to close in on them. Lee’s army found it hard to keep track of the Union troop movements as his ‘scout’, General Jeb Stuart, had become embroiled in battles at Brandy Station and Aldie, taking three cavalry brigades with him. On 1 July, Lee concentrated his army in the town of Gettysburg, Pennsylvania, where, in a ‘chance meeting’, he encountered Union cavalry and infantry corps.