The day before General Grant attacked Fort Donelson, the troops had had a march of twenty miles, part of it during a bitter cold night. Grant called a council of war to consider whether they should attack the fort at once, or should give the troops a day or two of rest. The officers were in favor of resting. Grant said nothing until they had all given their opinion; then he said: "There is a deserter who came in this morning, let us see him and hear what he has to say." When he came in, Grant looked into his knapsack. "Where are you from ?" "Fort Donelson." "Six days' rations in your knapsack, have you not, my man?" "Yes, Sir." "When were they served out?" "Yesterday morning." "Were the same rations served out to all the troops ?" "Yes, Sir." "Gentlemen," said Grant, " troops do not have six days' rations served out to them in a fort if they mean to stay there. These men mean to retreat, not to fight: we will attack at once. His action was as good as his word, and the eagles of victory soon perched upon his glorious banners.
From The Pictorial Book of Anecdotes and Incidents of the War of the Rebellion