As to how Lee occupied himself during this period, we may quote an anecdote coming from General Magruder.
"After the fall of Mexico, when the American army was enjoying the ease and relaxation which it had bought by toil and blood, a brilliant assembly of officers sat over their wine discussing the operations of the capture and indulging hopes of a speedy return to the United States.
"One among them rose to propose the health of the Captain of Engineers who had found a way for the army into the city, and then it was remarked that Captain Lee was absent. Magruder was despatched to bring him to the hall, and, departing on his mission, at last found the object of his search in a remote room of the palace, busy on a map. Magruder accosted him and reproached him for his absence. The earnest worker looked up from his labors with the calm, mild gaze which was so characteristic of the man, and, pointing to his instruments, shook his head.
"'But,' said Magruder, in his impetuous way, 'this is mere drudgery. Make somebody else do it, and come with me.'
"'No,' was the reply; 'no, I am but doing my duty.'"
This is very significant of Lee's subsequent character, in which the demands of duty always outweighed any thought of pleasure or relaxation, and in which his remarkable ability as an engineer was of inestimable advantage to the cause he served.