Heavy rain fell over the Gettysburg battlefield during the previous night and continued all through the next day as the Armies of the Potomac and Northern Virginia faced each other. In the evening, General Lee's troops began a withdrawal from Pennsylvania, his trains of wounded and artillery moving first and then his main force. The retreat continued for several days, reaching Hagerstown and then the crossing point of the Potomac at Williamsburg on the evening of July 6, 1863. (By John Osborne)