"That is now the great strategic line of the western campaign, and I am surprised that General Buell should hesitate to reinforce me. He was too late at Fort Donelson.... Believe me, General, you make a serious mistake in having three independent commands in the West. There never will and never can be any cooeperation at the critical moment; all military history proves it." This insistence had greater point because of the news received that Curtis, energetically following Price into Arkansas, had won a great Union victory at Pea Ridge, between March 5 and 8, over the united forces of Price and McCulloch, commanded by Van Dorn. At this juncture, events at Washington, hereafter to be mentioned, caused a reorganization of military commands and President Lincoln's Special War Order No. 3 consolidated the western departments of Hunter, Halleck, and Buell, as far east as Knoxville, Tennessee, under the title of the Department of the Mississippi, and placed General Halleck in command of the whole. Meanwhile, Halleck had ordered the victorious Union army at Fort Donelson to move forward to Savannah on the Tennessee River under the command of Grant; and, now that he had superior command, directed Buell to march all of his forces not required to defend Nashville "as rapidly as possible" to the same point. Halleck was still at St. Louis; and through the indecision of his further orders, through the slowness of Buell's march, and through the unexplained inattention of Grant, the Union armies narrowly escaped a serious disaster, which, however, the determined courage of the troops and subordinate officers turned into a most important victory. The "golden opportunity" so earnestly pointed out by Halleck, while not entirely lost, was nevertheless seriously diminished by the hesitation and delay of the Union commanders to agree upon some plan of effective cooeperation. When, at the fall of Fort Donelson the Confederates retreated from Nashville toward Chattanooga, and from Columbus toward Jackson, a swift advance by the Tennessee River could have kept them separated; but as that open highway was not promptly followed in force, the flying Confederate detachments found abundant leisure to form a junction.