colonel frederick winthrop's brigade of brigadier general romeyn b. ayres's division of the v corps took a further advance position across gravelly run near the confederate white oak road line in torrential rain on march 30, 1865. ayres was unaware of how close his men were settling in near the confederate white oak road line and that contrary to his observation and belief, the confederate line extended beyond the end of his new position. this, and the separation between ayres's corps and sheridan's cavalry, were important factors when ayres's troops were surprised by a confederate attack the next day. warren's corps, led by brevet major general charles griffin's first division, counterattacked, pushed the confederates back to their original lines, secured advanced positions and cut the confederates access to direct communication with pickett over white oak road and the boydton plank road. after securing his position, warren also was able to send units to outflank and drive off pickett's forces which were in a position to inflict a serious defeat on sheridan's troopers whom pickett's force had pushed back that day at dinwiddie court house.