William A. Crafts, Life of Ulysses S. Grant: His Boyhood, Campaigns, and Services, Military and Civil.

[41] to enthusiastic and even brilliant soldiers, appeared inexplicable. A great commander, it was imagined, should be nervous, excitable, inspiring his men and captivating his officers; calling private soldiers by their names, making eloquent addresses in the field, and waving his drawn sword in battle. Great commanders had done all these things and won; and many men, who could do all these things, fancied themselves, therefore, great commanders. Others imagined wisdom to consist in science alone; they sought success in learned and elaborate plans, requiring months to develop, when the enemy was immediately before them; they manoeuvred when it was time to fight; they intrenched when they should have attacked, and studied books when the field should have been their only problem.

Grant was like none of these. If he possessed acquirements, he appeared unconscious of them; he made no allusions to the schools, and never hesitated to transgress their rules when the occasion seemed to him to demand it. So he neither won men's hearts by blandishments, nor affected their imaginations by brilliancy of behavior; nor did he seem profound to those who are impressed only by a display of learning.

But by his career, when uncontrolled by his superiors, he proved to these sceptics that he possessed both intellectual ability and military genius, and upset their preconceived notions of a great commander.

Grant did not have a very exalted opinion of “strategy” in the common acceptation of the word, though he was in fact a successful strategist and a master of grand tactics.