By the early summer of 1861, Americans in both the North and South met the outbreak of war with patriotism and expectations of a quick decisive battle. In the North, public pressure for an immediate invasion led President Lincoln to order Gen. Irvin McDowell to submit a plan to advance on the important railroad junction at Manassas, despite professional soldiers urging patience. Anticipating a Federal attack, on July 17, 1861, Gen. Pierre G. T. Beauregard ordered Confederate forces to leave the extensive earthworks on the open plains at Centreville and withdraw behind the strong naturally wooded defensive position of Bull Run, where steep banks and impassable approaches meant the Federals would have to cross at the fords and bridges. This position improved Confederate chances for victory and protected the vital railroad junction at Manassas, which supplied and reinforced the Southern army. On July 21, 1861, at the Battle of First Manassas, the first tactical use of railroads in history to deliver troops to combat brought three Confederate brigades, 9,000 men under General Joseph E. Johnston, from the Shenandoah Valley to Manassas Junction.
