...out daylight the enemy opened a heavy fire of artillery on our guns in position, which was promptly returned. Their fire was silenced for the time, but it was frequently renewed during the day. General McClellan 's plan was to attack the enemy's left with the corps of Hooker and Mansfield, supported by Sumner's, and, if necessary, by Franklin's; and, in case of success at this point, to move Burnside's corps ...