"Let me see some of those haversacks," he commanded sharply, and one glance at their contents convinced him that the Confederates were not attempting to crush his army, but were trying to break through his lines and escape. If they intended to stay and defend the fortress, they would not carry haversacks at all; but if they contemplated a retreat, they would not only take them, but fill them with enough provisions to last for several days. In reaching this conclusion Grant was greatly aided by his knowledge of the men opposing him. He had served in Mexico with General Pillow, the second in command at Fort Donelson, and, knowing him to be a timid man, felt certain that nothing but desperation would ever induce him to risk an attack. He also knew that Floyd, his immediate superior, who had recently been the United States Secretary of War, had excellent reasons for avoiding capture and, putting all these facts together, he instantly rose to the occasion. "Fill your cartridge boxes, quick, and get into line," was his order to the men as he dashed down the wavering lines. "The enemy is trying to escape and he must not be permitted to do so!" The word flew through the disordered ranks, transforming them as it passed, and at the same time orders were issued for the entire left wing to advance and attack without a moment's delay. This unexpected onslaught quickly threw the Confederates back into the fortress, but before they again reached the shelter of its walls the Union forces had carried all the outer defenses and had virtually locked the door behind their retreating adversaries. From that moment the capture of the imprisoned garrison was only a question of time, and within twenty-four hours Grant received a communication from the Confederate commander asking for a truce to consider the terms of surrender. To his utter astonishment, however, this suggestion did not come from either General Floyd or General Pillow but from Simon Buckner, his old friend at West Point, who had so generously aided him when he reached New York, penniless and disgraced after his resignation from the army. This was an embarrassing situation, indeed, but while he would have done anything he could for Buckner personally, Grant realized that he must not allow gratitude or friendship to interfere with his duty. He, therefore, promptly answered the proposal for a truce in these words: "No terms except an unconditional and immediate surrender can be accepted. I propose to move immediately upon your works." [NOTE from Brett: The full letter is also shown in Grant's handwriting which leaves something to be desired. I will do my best to transcribe it below: Hd Qrs. Army in the Field Camp Fort Donelson, Feb. 16th 1862 Cmdr. S. B. Buckner Confed. Army. Sir, Yours of this inst. proposing armistice, and appointment of Commissioners to settle terms of Capitulation is just received. No terms except an unconditional and immediate surrender can be accepted.