[After repeated requests Grant secured permission, February 1st, to
undertake the campaign up the Tennessee. Fort Henry was captured on
the 6th; Fort Donelson, eleven miles away, fell on the 16th. Fort
Donelson was on high ground, one hundred feet above the Cumberland
River. It was an important position for the enemy. Generals Floyd and
Pillow, first and second in command at Port Donelson, escaped during
the night of the 15th. General Buckner, who was forced to surrender
the fort, said to Grant that if he, Buckner, had been in command Grant
would never have reached Donelson as easily as he did. Grant answered,
"In that case I should not have tried in the way I did; I relied upon
Pillow to allow me to come up within gunshot of any entrenchments he
was given to hold." Pillow had been in the Mexican War and he prided
himself upon that service. Grant speaks of his own service in the
Mexican War as being invaluable to him as he there came to know all
the men who, later on, held conspicuous positions in both the Northern
and Southern armies; he learned to know their strong points and their
weaknesses, and to infer how they would act under given conditions.