In his prime Lee was spoken of as the handsomest man in the army. He was about six feet high, perfectly built, healthy, fond of outdoor life, enthusiastic in his profession, gentle, dignified, studious, broad-minded, and positively, though unobtrusively, religious. If he had faults, which those nearest him doubted, they were excess of modesty and excess of tenderness. During the Mexican War, Captain Lee directed all the most important engineering operations of the American army--a work vital to its wonderful success. Already at the siege of Vera Cruz, General Scott mentioned him as having "greatly distinguished himself." He was prominent in all the operations thence to Cerro Gordo, where, in April, 1847, he was brevetted major. Both at Contreras and at Churubusco he was credited with gallant and meritorious services. At the charge up Chapultepec, in which Joseph E. Johnston, George B. McClellan, George E. Pickett, and Thomas J. Jackson participated, Lee bore Scott's orders to all points until from loss of blood by a wound, and from the loss of two nights' sleep at the batteries, he actually fainted away in the discharge of his duty. Such ability and devotion brought him home from Mexico bearing the brevet rank of colonel. General Scott had learned to think of him as "the greatest military genius in America." In 1852 Lee was made superintendent of the West Point Military Academy. In 1855 he was commissioned lieutenant-colonel of Col. Albert Sidney Johnston's new cavalry regiment, just raised to serve in Texas. March, 1861, saw him colonel of the First United States Cavalry. With the possible exception of the two Johnstons, he was now the most promising candidate for General Scott's position whenever that venerable hero vacated it, as he was sure to do soon. Lee was a Virginian, and Virginia, about to secede and at length seceding, in most earnest tones besought her distinguished son to join her. It seemed to him the call of duty, and that call, as he understood it, was one which it was not in him to disobey. President Lincoln knew the value of the man, and sent Frank Blair to him to say that if he would abide by the Union he should soon command the whole active army. That would probably have meant his election, in due time, to the presidency of his country. "For God's sake don't resign, Lee!" General Scott--himself a Virginian--is said to have pleaded. He replied: "I am compelled to; I cannot consult my own feelings in the matter." Accordingly, three days after Virginia passed its ordinance of secession, Lee sent to Simon Cameron, Secretary of War, his resignation as an officer in the United States army.