... artillery; and at 4.10 P. M., the hour Jackson was forming his column of attack behind his right, Hooker sent a dispatch to Sedgwick: We know the enemy is flying, trying to save his trains. Two of Sickles 's divisions are among them. About 3 P. M. Jackson's van reached the plank road, three miles west of Chancellorsville. The commander of the cavalry accompanying him had made a personal reconno...