Actually, fighting over the same ground was not uncommon in the CW, particularly in the Virginia seat of war. That is not surprising given the relatively small geographical area in which hostilities see-sawed over 4 years. The Shenandoah Valley was a natural "highway" and communications route for invading armies of both sides to contest, the Rappahannock/Rapidan river lines provided defensive positions for the Confederacy and jumping off points for the Union, and the Richmond/Petersburg axis was a hotly contested location for both sides. Second Manassas is only one of the many battles that were fought over similar ground; others include Winchester, Cold Harbor (Gaines Mill), and the Wilderness.