Since the fall of Fort Henry on February 6, a lively correspondence had been going on, in which General Halleck besought Buell to come with his available forces, assist in capturing Donelson, and command the column up the Cumberland to cut off both Columbus and Nashville. President Lincoln, scanning the news with intense solicitude, and losing no opportunity to urge effective cooeperation, telegraphed Halleck: "You have Fort Donelson safe, unless Grant shall be overwhelmed from outside: to prevent which latter will, I think, require all the vigilance, energy, and skill of yourself and Buell, acting in full cooeperation. Columbus will not get at Grant, but the force from Bowling Green will. They hold the railroad from Bowling Green to within a few miles of Fort Donelson, with the bridge at Clarksville undisturbed. It is unsafe to rely that they will not dare to expose Nashville to Buell. A small part of their force can retire slowly toward Nashville, breaking up the railroad as they go, and keep Buell out of that city twenty days. Meantime, Nashville will be abundantly defended by forces from all south and perhaps from here at Manassas. Could not a cavalry force from General Thomas on the upper Cumberland dash across, almost unresisted, and cut the railroad at or near Knoxville, Tennessee? In the midst of a bombardment at Fort Donelson, why could not a gunboat run up and destroy the bridge at Clarksville? Our success or failure at Fort Donelson is vastly important, and I beg you to put your soul in the effort. I send a copy of this to Buell." This telegram abundantly shows with what minute understanding and accurate judgment the President comprehended military conditions and results in the West. Buell, however, was too intent upon his own separate movement to seize the brilliant opportunity offered him. As he only in a feeble advance followed up the retreating Confederate column from Bowling Green to Nashville, Halleck naturally appropriated to himself the merit of the campaign, and telegraphed to Washington on the day after the surrender: "Make Buell, Grant, and Pope major-generals of volunteers, and give me command in the West. I ask this in return for Forts Henry and Donelson."