midnight
His forces and his movements were covered by streams , forests , hills , and by a very heavy chaparral or copse for miles in extent . `` Silent would not attack in his front , as Laws expected , but concluded to plunge immediately into the chaparral and threaten Laws 's right . This would compel the enemy to give battle at once or retreat . So orders were issued for the Army of the East to move at midnight , cross the Rapidan , and march into the dense woods by the roads nearest the rebel lines . The troops moved , and by dawn the next morning had possession of the crossings and were passing over the river . By night of that day the army had crossed with most of their trains . The cavalry had pushed forward and camped near Sedgewear , who had gone into bivouac on the hill after crossing the Rapidan .