whole affair was a mistake on the part of the commander.  His troops had been heedlessly pushed forward, and General Longstreet, commanding the opposing brigade, by carefully concealing his infantry, had drawn him into an ambuscade.  The results of the action were not without importance.  The Federals fell back with a loss of 83 officers and men, and the Confederates were much elated at their easy success.  Among some of the Northerners, on the other hand, the sudden check to the advance, and the bold bearing of the enemy, turned confidence and enthusiasm into irrational despondency.  A regiment and a battery, which had enlisted for three months and whose time was up, demanded their discharge, and notwithstanding the appeals of the Secretary of War, “moved to the rear to the sound of the enemy’s cannon."* (* O.R. volume 2 page 324.  McDowell’s Report.)

McDowell’s plans were affected by the behaviour of his troops.  He was still ignorant, so skilfully had the march from the Valley been carried out, that Johnston had escaped Patterson.  He was well aware, however, that such movement was within the bounds of possibility, yet he found himself compelled to postpone attack until the 21st.  The 19th and 20th were spent in reconnaissance, and in bringing up supplies; and the lack of organisation made the issue of rations a long process.  But it was the general’s want of confidence in his soldiers that was the main cause of delay.

The Confederates were strongly posted.  The bridges and fords across Bull Run, with the exception of Sudley Ford, a long way up stream to the Federal right, were obstructed with felled trees, and covered by rude intrenchments.  Even with regular troops a direct attack on a single point of passage would have been difficult.  McDowell’s first idea was to pass across the front of the defences, and turn the right at Wolf Run Shoals, five miles south-east of Union Mills.  The country, however, on this flank was found to be unfit for the operations of large masses, and it was consequently determined to turn the Confederate left by way of Sudley Springs.

The Federal army consisted of five divisions of infantry, forty-three guns, and seven troops of regular cavalry.  Nine batteries and eight companies of infantry were supplied by the United States army, and there was a small battalion of marines.  The strength of the force told off for the attack amounted to 30,000 all told.*

(* The rifles (muzzle-loaders) used throughout the war by both
Federals and Confederates compare as follows with more modern
weapons:—­
                            Sighted to Effective range
                            yards yards
American 1,000 250
Needle-gun (1866 and 1870) 660 250
Chassepot (1870) 1,320 350
Martini-Henry 2,100 400
Magazine 3,200 600