Something just occurred to me, and I'm embarrassed it took me this long. The whole objective for armies in the war was other armies, not cities, not even capitals. In the Civil War the Army holed up in Ft. Donelson was captured. The Confederate Army at Shiloh was nearly destroyed, the Confederate Army of the Mississippi was lost at Vicksburg, the Confederate Army at Missionary Ridge was scattered, and the newly formed Army of Tennessee was totally destroyed at Nashville. This was 5 Confederate Armies lost or scattered to the four winds. This NEVER happened to the North!
Destroying a Northern Army, preferably the Army of the Potomac, and doing it north of Washington, was the South's true strategic objective. Bad as the results of 1st Bull Run were, Patterson's army in the Shenandoah was still available to cover the city. Considering the shape of Patterson's forces versus the Southern forces, it's very hard to see how such an exhausted force could overwhelm such a sizable force as Patterson's while they were still moderately fresh. Was there ever another chance? Chickamauga, perhaps? Or was that too late in the war?