Patterson's command of roughly 15,000 troops should have supported the Union attack, but it never entered the battle. Its position still mattered because the Confederate army could not ignore a fresh force nearby. McDowell also retained 30,000 or more disorganized but surviving troops after the defeat. The same readiness and coordination problems that hurt the Union therefore limited Confederate pursuit, so victory at Bull Run did not open a practical route to Washington.
Notable Point · 10:28-12:22
Patterson's idle army still checks pursuit
Patterson's roughly 15,000 unused troops fail to help McDowell, yet their position and the Union forces still intact after defeat make a Confederate advance on Washington impractical.