THE retreat from Chancellorsville began on the fourth of May, in 1863. In the midst of a pouring rain, with ammunition wagons and cavalry struggling hub-deep through the mud, the Federals moved back to the Rappahannock. The ponderous batteries, with heavy wheels wrapped in blankets, passed over the road. Then came the ordnance supply trains, swathed in strips of cloth, followed by columns of hurrying infantry. During the remainder of May, neither of the armies assumed an offensive attitude. Lee, now in high hopes, began preparations for a second invasion in Maryland. Panic again seized the people of the North. Lincoln called on Pennsylvania for 50,000 militia; Ohio, 30,000; New York, 20,000; Maryland and Virginia, 10,000 each. The Army of the Potomac had lost all of its two years' service men and its strength did not reach 100,000. The Confederacy had been endeavoring for months to induce England to recognize it as a separate nation, but learned that it must first conquer Northern territory. Lee's movements began early in June and resulted in frequent skirmishes as he approached the Potomac. This photograph was taken immediately after one of these encounters at Aldie, Virginia, on the seventeenth of June, 1863. The Confederate cavalry, under "Jeb" Stuart, was guarding the passes of the Bull Run mountains and watching Hooker's Army. There was a succession of cavalry combats and many Confederates were taken prisoners. This view shows a group of Confederates under a Union guard composed largely of negro soldiers.