...ongeth, without whose favor and support our efforts must all prove vain. The lack of knowledge as to the whereabouts and intentions of Meade, because of the absence of his cavalry, delayed Lee at Chambersburg ; but on the night of the 28th, Harrison, a daring Virginia scout in the service of Longstreet, reached him with the information, the first he had received, that the army of the Potomac had crossed th...