But Lee and Jackson had not to deal with ordinary conditions.  Whatever may have been the case in the Peninsula and in the Valley, there can be no question but that the armies in Maryland were by no means equal in quality.  The Federals were far more accustomed to retreat than advance.  For several months, whether they were engaged on the Shenandoah, on the Chickahominy, on the Rappahannock, or on Bull Run, they had been invariably outmanoeuvered.  Their losses had been exceedingly severe, not only in battle, but from sickness and straggling.  Many of their bravest officers and men had fallen.  With the exception of the Second and Sixth Army Corps, commanded by Sumner and by Franklin, by far the greater part of the troops had been involved in Pope’s defeat, and they had not that trust in their leaders which promises a strong offensive.  While at Washington the army had been reinforced by twenty-four regiments of infantry, but the majority of these troops had been but lately raised; they knew little of drill; they were commanded by officers as ignorant as themselves, and they had never fired a musket.  Nor were the generals equal in capacity to those opposing them.  “If a student of history,” says a Northern officer, “familiar with the characters who figured in the War of Secession, but happening to be ignorant of the battle of Antietam, should be told the names of the men who held high commands there, he would say that with anything like equality of forces the Confederates must have won, for their leaders were men who made great names in the war, while the Federal leaders were, with few exceptions, men who never became conspicuous, or became conspicuous only through failure."* (* The Antietam and Fredericksburg.  General Palfrey page 53.) And the difference in military capacity extended to the rank and file.  When the two armies met on the Antietam, events had been such as to confer a marked superiority on the Southerners.  They were the children of victory, and every man in the army had participated in the successes of Lee and Jackson.  They had much experience of battle.  They were supremely confident in their own prowess, for the fall of Harper’s Ferry had made more than amends for the retreat from South Mountain, and they were supremely confident in their leaders.  No new regiments weakened the stability of their array.  Every brigade and every regiment could be depended on.  The artillery, which had been but lately reorganised in battalions, had, under the fostering care of General Pendleton, become peculiarly efficient, although the materiel was still indifferent; and against Stuart’s horsemen the Federal cavalry was practically useless.

In every military attribute, then, the Army of Northern Virginia was so superior to the Army of the Potomac that Lee and Jackson believed that they might fight a defensive battle, outnumbered as they were, with the hope of annihilating their enemy.  They were not especially favoured by the ground, and time and means for intrenching were both wanting; but they were assured that not only were their veterans capable of holding the position, but, if favoured by fortune, of delivering a counterstroke which should shiver the Army of the Potomac into a thousand fragments.