...t Williamsport. Johnson crossed the river on the 18th at Shepherdstown. Early did not cross until two day's inter, owing to high water. On the 20th Rodes and Johnson moved through Hagerstown to Greencastle , and Early crossed the river and moved to Cavetown; and so the invasion of Pennsylvania had begun. On the 24th the whole of A. P. Hill's corps crossed the Potomac at Shepherdstown, that of Long...