jackson's victory at front royal caused union general nathaniel banks to move his forces from strasburg and retreat to winchester. with jackson now on his right flank, banks was in danger of being cut off from his base at winchester. president lincoln felt jackson's army in the shenandoah valley threatened the safety of washington d.c. he ordered general irvin mcdowell's corps to hold their position at fredericksburg, virginia and not join mcclellan's union push towards richmond.