The story of the wrestle with these and other disabilities during the next four years is interesting and instructive. Three extracts from a list of rules for his personal conduct, set down at this time in a private note-book, sound the keynote of his subsequent career:
"Sacrifice your life rather than your word.
"Resolve to perform what you ought; perform without fail what you resolve.
"You may be whatever you resolve to be."
He was respected by all his classmates, known and liked by a few. He was too reserved by nature, too busy in practice, to be a general favorite. His labors were unremitting, his recreations few and simple. With no prevision of the destinies awaiting them, Jackson, McClellan, A. T. Hill, Reno, Picket, Foster, and Maury, as beardless boys, studied and were drilled side by side for four terms and were graduated upon the same day. There were seventy in this remarkable class, and the name of Thomas Jonathan Jackson stood seventeenth upon the roll of merit.
"If we had to stay here one year more, old Jack would be at the head," the witnesses of the fierce ordeal of his West Point training used to say.
The class of '46 was ordered forthwith to the seat of war in Mexico. Jackson's first engagement was the siege of Vera Cruz; his next the battle of Cherubusco. The official report of this last mentions him favorably. As second lieutenant, he was called upon early in the action to take the place of the next in rank above him, the first lieutenant having fallen in the charge. After the battle Jackson was further promoted to the rank of brevet captain. His "devotion, industry, talent, and gallantry" were noted officially after Chapultepec, not only by his colonel, but by Generals Pillow and Worth, and by the Commander-in-chief, Winfield Scott.
What he afterward confessed as the "one wilful lie he ever told" is thus reported by a brother-officer:
"Lieutenant Jackson's section of Magruder's battery was subjected to a plunging fire from the Castle of Chapultepec. Horses were killed or disabled, and the men deserted the guns and sought shelter behind wall or embankment. Lieutenant Jackson remained at the guns, walking back and forth and kept saying, 'See, there is no danger; I am not hit!' While standing with his legs wide apart, a cannon-ball passed between them.... No other officer in the army in Mexico was promoted so often for meritorious conduct, or made so great a stride in rank."
After peace was declared in 1848, he was stationed for two years at Fort Hamilton, and six months at Fort Meade in Florida; in 1851 he was elected Professor of Natural and Experimental Philosophy and Artillery Tactics in the Virginia Military Institute, situated in Lexington, Va. In the decade succeeding this event, he was to the casual eye the least striking figure in the group of professors who taught the art of war in the beautiful mountain-girt "West Point of the South."