Rosecrans's plan of campaign--Approved by McClellan with modification--Wagons or pack-mules--Final form of plan--Changes in commands--McClellan limited to Army of the Potomac--Halleck's Department of the Mississippi--Fremont's Mountain Department--Rosecrans superseded--Preparations in the Kanawha District--Batteaux to supplement steamboats--Light wagons for mountain work--Fremont's plan--East Tennessee as an objective--The supply question--Banks in the Shenandoah valley--Milroy's advance--Combat at McDowell--Banks defeated--Fremont's plans deranged--Operations in the Kanawha valley--Organization of brigades--Brigade commanders--Advance to Narrows of New River--The field telegraph--Concentration of the enemy--Affair at Princeton--Position at Flat-top Mountain. As the spring of 1862 approached, the discussion of plans for the opening of a new campaign was resumed. Rosecrans had suggested, early in February, that he would prefer to attempt reaching the Virginia and East Tennessee Railroad by two columns moving simultaneously upon Abingdon in the Holston valley. One of these would start from Gauley Bridge and go by way of Fayette, Raleigh, and Princeton; the other would leave some point in the Big-Sandy valley on the common boundary of Kentucky and Virginia, and march by most direct route to Abingdon. [Footnote: Official Records, vol. v. p. 721.] If this plan were approved, he asked that the west side of the Big-Sandy valley be added to his department. He proposed to depend largely upon pack-mule trains in place of wagons, to substitute the French shelter tent for the larger tents still in use, and to carry hand-mills by which the soldiers might grind into meal the Indian corn to be found in the country. McClellan, as general-in-chief, gave his approval, suggesting a modification in regard to the column to move from the Big-Sandy valley. His information led him to believe that the Big-Sandy River could be relied upon as navigable to Prestonburg, which was seventy miles from Abingdon by what was supposed to be a good road. He thought, therefore, that it would be easier to make Prestonburg the base and to use wagons. [Footnote: O, R., vol. v. p. 722.] On investigation Rosecrans reported that the most feasible route in that region was by steamboat transportation to Pikeville, twenty-five miles above Prestonburg, in the Big-Sandy valley, and thence up the Louisa Fork of the Big-Sandy by way of Pound Gap to the Holston valley; but there would still be eighty-eight miles of marching after leaving the steamboats, and navigation on the Big-Sandy was limited to brief and infrequent periods of high water.