Lincoln was, by now, beginning to assume the mantle of the presidency. While he still hesitated on some decisions—critics liked to say that he always preferred delay to action—Lincoln was now convinced of the righteousness of the Northern cause. Once that “why” was settled in his mind, the various answers to “how” became easier for him. Lincoln realized that he contributed to the defeat at Bull Run because of the way he had hurried General McDowell: from that point on, Lincoln deferred to his commanders in terms of timing (sometimes he did so to a fault).
A staff and supply officer with little battlefield experience, General Irvin McDowell was ill prepared and consequently met defeat at the First Battle of Bull Run.